DM310R2_LearnerGuide_RevD

BusinessObjects XI R1/R2: UniverseDesign

Learner’s GuideDM310R2

Revision D, March 2008

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C O N T E N T S

About this CourseCourse introduction...................................................................................................xiiiCourse description.....................................................................................................xivCourse audience.........................................................................................................xivPrerequisites................................................................................................................xivLevel, delivery, and duration...................................................................................xivApplicable certifications and designations.............................................................xivCourse success factors.................................................................................................xvCourse setup.................................................................................................................xvCourse materials..........................................................................................................xvLearning process..........................................................................................................xv

Lesson 1Understanding BusinessObjects UniversesLesson introduction.......................................................................................................1BusinessObjects universe concepts.............................................................................2

What is a universe?................................................................................................2The Semantic Layer................................................................................................3What type of database schema is used?..............................................................4Classes and objects ................................................................................................5How universes are used .......................................................................................5Advantages of a universe .....................................................................................6BusinessObjects Universe Designer components .............................................6Starting Designer ...................................................................................................6Using the Quick Design Wizard..........................................................................8Using Designer module commands ...................................................................8Saving and exporting a universe.......................................................................12Importing a universe ..........................................................................................12Universe file names as identifiers .....................................................................13Saving a universe definition as a PDF ..............................................................13Giving all users access to a universe ................................................................14Activity: Viewing a universe in Designer.........................................................14

The Universe Development Cycle ............................................................................16The Universe Development Cycle process ......................................................16Preparation phase ................................................................................................17Analysis phase......................................................................................................18Planning phase.....................................................................................................20

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Implementation phase.........................................................................................21Implementation phase 1: schema design..........................................................21Implementation phase 2: building the universe..............................................23Testing phase........................................................................................................24Deployment phase...............................................................................................25Updating/maintenance.......................................................................................26Prepackaged solutions.........................................................................................26Activity: Planning a universe.............................................................................27

Quiz: Understanding BusinessObjects universes...................................................28Lesson summary..........................................................................................................29

Lesson 2Creating the Course UniverseLesson introduction.....................................................................................................31The course database and universe ...........................................................................32

Course database description...............................................................................32Creating the universe .................................................................................................34

Creating a new universe......................................................................................34Defining universe parameters ...........................................................................35Identifying the universe......................................................................................35Setting the database connection.........................................................................36Data access drivers...............................................................................................37ODBC connection drivers...................................................................................38More about connection types.............................................................................40Viewing, modifying, and deleting available connections..............................43Universe parameters............................................................................................45Definition tab........................................................................................................46Summary tab.........................................................................................................46Strategies tab.........................................................................................................48Controls tab...........................................................................................................49SQL tab...................................................................................................................49Links tab................................................................................................................50Parameters tab......................................................................................................51Activity: Creating a new universe and defining its connection....................52

Quiz: Creating the course universe...........................................................................53Lesson summary..........................................................................................................54

Lesson 3Building the Universe StructureLesson introduction.....................................................................................................55Populating the universe structure.............................................................................56

Designing a schema ............................................................................................56Schema design and the universe creation process..........................................56Adding tables .......................................................................................................56

Universe Design—Learner’s Guideiv

Manipulating tables in the universe structure.................................................59Activity: Populating the universe structure.....................................................62

Defining joins in a universe........................................................................................64About joins and SQL WHERE clauses .............................................................64Creating joins........................................................................................................65About join properties...........................................................................................67Editing the join expression .................................................................................68Using the Join SQL editor ..................................................................................68Detecting joins .....................................................................................................69Setting join cardinalities......................................................................................70About cardinality.................................................................................................70Setting cardinality manually or with the automatic detection tool..............71Displaying cardinalities ......................................................................................73Detecting cardinality automatically..................................................................75How is cardinality detected?..............................................................................75Detect cardinality for all joins.............................................................................76Best practice for setting join cardinality ...........................................................77Join types ..............................................................................................................78Equi-joins ..............................................................................................................78Outer joins ............................................................................................................79Theta joins.............................................................................................................80Shortcut joins........................................................................................................82Self-restricting joins .............................................................................................83List Mode...............................................................................................................85Checking integrity ...............................................................................................87Activity: Defining joins in a universe................................................................87

Quiz: Building the universe structure......................................................................90Lesson summary..........................................................................................................91

Lesson 4Creating Dimension ObjectsLesson introduction.....................................................................................................93Classes and objects ......................................................................................................94

Classes....................................................................................................................94Objects....................................................................................................................95

Creating classes and objects ......................................................................................97Creating classes....................................................................................................97Automatically creating classes and objects from a table ...............................99Defining a new object as a detail object............................................................99Working with classes and subclasses..............................................................100Editing the object properties.............................................................................101Edit Properties: Properties................................................................................104Edit Properties: Advanced................................................................................105Edit Properties: Keys..........................................................................................106Edit Properties: Source Information................................................................107

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Copying and pasting objects.............................................................................108Find and replace ................................................................................................108Checking object integrity .................................................................................109Viewing parent tables........................................................................................110Testing objects ....................................................................................................111Activity: Creating and testing classes and objects.........................................111

Quiz: Creating dimension objects...........................................................................117Lesson summary........................................................................................................118

Lesson 5Creating Measure ObjectsLesson introduction...................................................................................................119Measure object concepts...........................................................................................120

Defining measure objects .................................................................................120How a measure infers SQL ..............................................................................120The Query Process .............................................................................................122Aggregation at SELECT level...........................................................................123Aggregation at projection level .......................................................................123Setting selection and projection aggregates...................................................124

Creating measure objects..........................................................................................125Measure objects .................................................................................................125Testing measure objects.....................................................................................126Activity: Creating and testing measure objects.............................................127

Quiz: Creating measure objects...............................................................................130Lesson summary........................................................................................................131

Lesson 6Using Lists of ValuesLesson introduction...................................................................................................133Creating a list of values ............................................................................................134

What is a list of values?.....................................................................................134Using a list of values (LOV)..............................................................................134

Working with LOVs in Designer ............................................................................135Associating an LOV with an object..................................................................135Setting options for generating LOVs ..............................................................137Editing the LOVs for the entire universe .......................................................138Adding data to the list by adding columns ...................................................139

Creating a cascading LOV .......................................................................................141Setting up a cascading LOV .............................................................................141Activity: Using a cascading LOV in Web Intelligence..................................142

Quiz: Using lists of values .......................................................................................144Lesson summary........................................................................................................145

Universe Design—Learner’s Guidevi

Lesson 7Resolving Loops in a UniverseLesson introduction...................................................................................................147Understanding loops ................................................................................................148

Recognizing loops..............................................................................................148Problems caused by loops ................................................................................148Loops in a universe schema and not in the database ...................................149What is the loop doing?.....................................................................................149Resolving loops ..................................................................................................150

Resolving loops using aliases ..................................................................................151About aliases ......................................................................................................151Detecting loops and inserting aliases .............................................................151Redefining objects .............................................................................................154Listing and renaming aliases ...........................................................................155Choosing which alias method to use ..............................................................155Resolving self-join loops using aliases............................................................155

Resolving loops using shortcut joins .....................................................................158Using a shortcut join..........................................................................................158Activity: Resolving loops with aliases............................................................159

Resolving loops using contexts ...............................................................................162About contexts....................................................................................................162Detecting and creating contexts ......................................................................165Creating objects for each context ....................................................................168Editing a context ................................................................................................168Testing contexts .................................................................................................169Updating contexts .............................................................................................170Activity: Resolving loops using contexts........................................................171

Quiz: Resolving loops in a universe .......................................................................176Lesson summary........................................................................................................177

Lesson 8Resolving SQL TrapsLesson introduction...................................................................................................179Understanding SQL traps and universes ..............................................................180

About SQL traps ................................................................................................180Detecting and resolving chasm traps .....................................................................181

Chasm traps .......................................................................................................181Detecting chasm traps ......................................................................................182The Chasm trap scenario ..................................................................................182Resolving chasm traps ......................................................................................185Using multiple SQL statements for each measure to resolve chasmtraps......................................................................................................................185

viiTable of Contents—Learner’s Guide

Drawbacks to the Multiple SQL statements for each measuremethod.................................................................................................................187Using contexts to resolve chasm traps ...........................................................188Activity: Resolving chasm traps.......................................................................190

Detecting and resolving fan traps ..........................................................................193Fan traps .............................................................................................................193The fan trap scenario ........................................................................................194Resolving fan traps.............................................................................................195Using aliases and contexts to resolve fan traps.............................................196Solving a fan trap with two tables in a one-to-many relationship..............198Avoiding fan traps altogether .........................................................................199Activity: Resolving fan traps............................................................................201

Quiz: Resolving SQL traps ......................................................................................205Lesson summary........................................................................................................206

Lesson 9Applying Restrictions on ObjectsLesson introduction...................................................................................................207Restricting the data returned by objects ................................................................208

Defining data restrictions .................................................................................208Methods of restricting data in end-user modules ........................................209Drawbacks to applying restrictions to objects ..............................................210An alternative to applying restrictions to objects .........................................211Restrictions using condition objects ...............................................................213Applying restrictions using the tables button ...............................................214Applying each type of restriction ...................................................................216Activity: Applying restrictions.........................................................................216

Quiz: Applying restrictions on objects ..................................................................219Lesson summary........................................................................................................220

Lesson 10Using @functions with ObjectsLesson introduction...................................................................................................221Using @functions.......................................................................................................222

Defining @functions ..........................................................................................222@prompt .............................................................................................................222@prompt syntax .................................................................................................223@select..................................................................................................................224@where.................................................................................................................226@aggregate_aware..............................................................................................230Activity: Using @functions...............................................................................230

Quiz: Using @functions with objects .....................................................................232Lesson summary........................................................................................................233

Universe Design—Learner’s Guideviii

Lesson 11Using HierarchiesLesson introduction...................................................................................................235Understanding hierarchies and universes ............................................................236

Hierarchies..........................................................................................................236Working with hierarchies ........................................................................................238

Default hierarchies ............................................................................................238Custom hierarchies............................................................................................241The effect of custom hierarchies on default hierarchies ..............................242Time hierarchies ................................................................................................244Testing automatic time hierarchies .................................................................247Advantages and disadvantages of automatic time hierarchies ..................248Time hierarchies based on database functions .............................................248Advantages and disadvantages of database function time hierarchies...............................................................................................................................249Table-based time hierarchies ...........................................................................250Advantages and disadvantages of table-based time hierarchies ...............251Activity: Using hierarchies................................................................................252

Quiz: Using hierarchies ............................................................................................254Lesson summary........................................................................................................255

Lesson 12Derived Tables and IndexesLesson introduction...................................................................................................257Using derived tables .................................................................................................258

What is a derived table?....................................................................................258Adding derived tables ......................................................................................258Derived tables as lookup for multiple contexts.............................................259Activity: Adding derived tables.......................................................................260

Applying index awareness ......................................................................................261What is index awareness?.................................................................................261Setting up index awareness..............................................................................261What happens behind the scenes?...................................................................263Avoiding joins in tables.....................................................................................265Multiple foreign key entries.............................................................................266SQL Editor dialog box ......................................................................................268Using an index awareness WHERE clause.....................................................268Activity: Setting up index awareness..............................................................269

Quiz: Derived tables and indexes ...........................................................................270Lesson summary........................................................................................................271

ixTable of Contents—Learner’s Guide

Lesson 13End-of-Course ChallengeLesson introduction...................................................................................................273End-of-course challenge............................................................................................274

Customer scenario..............................................................................................274Activity: End-of-course challenge - Part 1......................................................275Activity: End-of-course challenge - Part 2......................................................277

Lesson summary........................................................................................................278

Appendix ARelational/Dimensional ModelingUnderstanding the metadata...................................................................................279Data warehouses........................................................................................................280Online Transactional Processing systems..............................................................281Data Marts...................................................................................................................282Dimensional Modeling..............................................................................................283

Appendix BAlternative SQL syntaxes for other RDBMSSQL syntaxes for other RDBMS...............................................................................285

Answer KeyQuiz: Understanding BusinessObjects universes.................................................291Quiz: Creating the course universe.........................................................................292Quiz: Building the universe structure....................................................................293Quiz: Creating dimension objects...........................................................................294Quiz: Creating measure objects...............................................................................295Quiz: Using lists of values .......................................................................................296Quiz: Resolving loops in a universe .......................................................................297Quiz: Resolving SQL traps ......................................................................................298Quiz: Applying restrictions on objects ..................................................................299Quiz: Using @functions with objects .....................................................................300Quiz: Using hierarchies ............................................................................................301Quiz: Derived tables and indexes ...........................................................................302

Universe Design—Learner’s Guidex

A G E N D AUniverse Design

Introductions, Course Overview...........................................30 minutes

Lesson 1Understanding BusinessObjects Universes.....................30 minutes❒ BusinessObjects universe concepts❒ The Universe Development Cycle

Lesson 2Creating the Course Universe...............................................45 minutes❒ The course database and universe❒ Creating the universe

Lesson 3Building the Universe Structure....................................................1 hour❒ Populating the universe structure❒ Defining joins in a universe

Lesson 4Creating Dimension Objects........................................................2 hours❒ Classes and objects❒ Creating classes and objects

Lesson 5Creating Measure Objects......................................................30 minutes❒ Measure object concepts❒ Creating measure objects

Lesson 6Using Lists of Values................................................................30 minutes❒ Creating a list of values❒ Working with LOVs in Designer❒ Creating a cascading LOV

xiAgenda—Learner’s Guide

Lesson 7Resolving Loops in a Universe....................................................3 hours❒ Understanding loops❒ Resolving loops using aliases❒ Resolving loops using shortcut joins❒ Resolving loops using contexts

Lesson 8Resolving SQL Traps...................................................................1.5 hours❒ Understanding SQL traps and universes❒ Detecting and resolving chasm traps❒ Detecting and resolving fan traps

Lesson 9Applying Restrictions on Objects.................................................1 hour❒ Restricting the data returned by objects

Lesson 10Using @functions with Objects............................................45 minutes❒ Using @functions

Lesson 11Using Hierarchies......................................................................45 minutes❒ Understanding hierarchies and universes❒ Working with hierarchies

Lesson 12Derived Tables and Indexes............................................................1 hour❒ Using derived tables❒ Applying index awareness

Lesson 13End-of-Course Challenge...........................................................2.5 hours❒ End-of-course challenge

Universe Design—Learner’s Guidexii

About this Course

Course introductionThis section explains the conventions used in the course and in this training guide.

xiiiAbout this Course—Learner’s Guide

Course descriptionThis three-day instructor-led course is designed to give you the comprehensive skills neededto design, build and maintain BusinessObjects 6.5 and BusinessObjects XI R1/R2 universes.

You should attend this course to understand universe design concepts and terminology, aswell as the role of universes in relation to BusinessObjects reporting tools. The course providesan overview of the process for planning, designing and creating a universe and thenwalks youthrough the process of designing a universe that responds to identified requirements.

The business benefit of this course is that youwill learn best-practicemethodology for creatinguniverses that respond to your reporting requirements. Through well-designed universes,report designers and business users will be able to create reports without having to knowanything about the underlying data source or structure.

Course audience

This course is designed to teach you how to design BusinessObjects universes using UniverseDesigner, using BusinessObjects 6.5 or BusinessObjects XI R1/R2.

New features covered in the XI R2 course that are not applicable to BusinessObjects 6.5 or XIR1 learners include:• Creating a cascading list of values associated with a hierarchy of objects in a universe

The target audience for this course is universe designers.

Prerequisites

To be successful, learnerswho attend this course should have attended the following offerings:• BusinessObjects Web Intelligence XI R1/R2: Report Design

To be successful, learners who attend this course should have the following experience:• SQL and relational database management systems concepts and structures• Familiarity with the type of data and the logical structure of the databases in their

organization• Familiarity with BusinessObjects Web Intelligence report building

Level, delivery, and duration

This core instructor-led offering is a three-day course.

Applicable certifications and designations

This course is not applicable to any Business Objects Certified Professional programs.

Universe Design—Learner’s Guidexiv

Course success factors

Your learning experience will be enhanced by:• Activities that build on the life experiences of the learner• Discussion that connects the training to real working environments• Learners and instructor working as a team• Active participation by all learners

Course setup

Refer to the setup guide for details on hardware, software, and course-specific requirements.

Course materials

The materials included with the course materials are:• Name card• Learner’s Guide

The Learner’s Guide contains an agenda, learner materials, and practice activities.

The Learner’s Guide is designed to assist students who attend the classroom-based courseand outlines what learners can expect to achieve by participating in this course.

• Evaluation form

At the conclusion of this course, you will receive an electronic feedback form as part of ourevaluation process. Provide feedback on the course content, instructor, and facility. Yourcomments will assist us to improve future courses.

Additional resources include:• Sample files

The sample files can include required files for the course activities and/or supplementalcontent to the training guide.

• OnlineHelp

Retrieve information and find answers to questions using the onlineHelp and/or user’sguide that are included with the product.

Learning process

Learning is an interactive process between the learners and the instructor. By facilitating acooperative environment, the instructor guides the learners through the learning framework.

Introduction

Why am I here? What’s in it for me?

The learners will be clear about what they are getting out of each lesson.

xvAbout this Course—Learner’s Guide

Objectives

How do I achieve the outcome?

The learners will assimilate new concepts and how to apply the ideas presented in the lesson.This step sets the groundwork for practice.

Practice

How do I do it?

The learners will demonstrate their knowledge as well as their hands-on skills through theactivities.

Review

How did I do?

The learners will have an opportunity to review what they have learned during the lesson.Review reinforces why it is important to learn particular concepts or skills.

Summary

Where have I been and where am I going?

The summary acts as a recap of the learning objectives and as a transition to the next section.

Universe Design—Learner’s Guidexvi

Lesson 1Understanding BusinessObjects Universes

Lesson introductionTo design effective and efficient universes for your business users, you need a generalunderstanding of their structure and application. It is also important to become familiar withthe process involved in building a successful universe.

After completing this lesson, you will be able to:

• Define BusinessObjects universe concepts• Use the Universe Development Cycle

1Understanding BusinessObjects Universes—Learner’s Guide

BusinessObjects universe conceptsThis lesson gives a general introduction to universes.

After completing this unit, you will be able to:

• Describe a universe• Describe BusinessObjects Universe Designer interface elements• Save, export, and import universes

What is a universe?

The BusinessObjects universe is the semantic layer that isolates business users from the technicalcomplexities of the databases where their corporate information is stored.

For the ease of the end user, universes are made up of objects and classes that map to data inthe database, using everyday terms that describe their business environment. This means thatby using a universe to create a query, users can retrieve exactly the data that interests themusing their own business terminology.

A BusinessObjects universe is a file that contains the following:• Connection parameters to a single data source.

• SQL structures called objects that map to actual SQL structures in the database such ascolumns, tables, and database functions. Objects are grouped into classes.

• A schema of the tables and joins used in the database. Objects are built from the databasestructures that you include in your schema.

Note:

You associate data to universes by mapping to a data source. Data is not stored in the .unv file.

Universe Design—Learner’s Guide2

End users select the universe they are authorized to access in order to build queries. They builda query by selecting objects defined in the universe, and in this way, they are not required tosee or know anything about the underlying data structures in the database.

BusinessObjectsDesigner XI Release 2 nowgives universe designers the ability to build universesfrom OLAP and metadata sources. It also offers the ability to build universes against Unicodedatabases and run reports that display data in one of many available languages.

Universes are used to query the database

The role of the universe is to present a business-focused front end to the SQL structures in thedatabase. The data used in a universe schema depends greatly on the end user requirements.It needs to provide an easy-to-use interface for end users to:• Run queries against a database

• Create reports

• Perform data analysis

The Semantic Layer

Designer can be seen as the tool which creates the Semantic Layer.

Metadata is imported intoDesigner, and then the tables structure can be changed (usingDerivedTables) or data can be changed before it is presented to the user (by manipulating objects).However, the source data essentially remains the same. This is what separates the SemanticLayer from Data Integrator.

Data Integrator is an ETL Tool which can change the structure of the data, and also cleanse itfrom data errors.


The semantic layer is also used for the PerformanceManagement product suite.When buildinga Dashboard Manager or Set Analysis Metrics universe, the approach is slightly different tocreating a normal ad hoc reporting universe:• the Dashboard Manager or Set Analysis Metrics universe requires custom tags embedded

within it (which can be considered a form of code), which are used by Dashboard Managerand Set Analysis products

• a mandatory self join is placed in the Dashboard Manager or Set Analysis Metrics universeto ensure that calculated metrics apply to one time period granularity in a time dimension,for example, daily, weekly, or monthly.

• custom filters are placed into the Dashboard Manager or Set Analysis Metrics universe tobe able to compare sets (Joiner Filter, Leaver Filter, and so on), and to build metrics.

This is why it is advisable not to use the same ad hoc reporting universe as your DashboardManager or Set Analysis Metrics universe.

Information on building a Dashboard Manager or Set Analysis Metrics universe can be foundin the Creating universes for use as metrics chapter of the BusinessObjects XI Release 2 Designer'sGuide.

What type of database schema is used?

Before developing a universe you must familiarize yourself with the underlying data. Whichtype of database schema is going to be used for the universe? Will this be a Data Warehousemodel, an Online Transactional Processing system (OLTP), or a Data Mart? How can you bestimplement the metadata into a universe schema to meet the end-user requirements?

Star Schemas

The star schema is the simplest data warehouse schema. It is called a star schema because thediagram resembles a star, with points radiating from a center. The center of the star consistsof one or more fact tables and the points of the star are the dimension tables.

A star schema consists of fact tables and dimension tables:• Fact tables

A fact table typically has two types of columns: numeric facts and foreign keys to dimensiontables. Facts can become measure objects in a BusinessObjects universe file.


• Dimension tables

Dimension tables contain the qualitative descriptions that can be applied to the facts.Hierarchies may also be built into dimension tables. Dimension table data can becomedimension or detail objects in a BusinessObjects universe file.

Snow flake schemas

The snowflake schema is a variation of the star schema used in a data warehouse. It is morecomplex than the star schema because the tableswhich describe the dimensions are normalized.

Data modeling

The traditional entity relationship (ER) model uses a normalized approach to database design.

Database normalization is a technique for designing relational database tables to minimizeduplication of information and to avoid data anomalies. Higher degrees of normalizationtypically involvemore tables and create the need for a larger number of joins, which can reduceperformance.

Denormalization is the process of taking a normalized database andmodifying table structuresto optimize the performance by keeping a minimum relationship between tables; 1 dimensiontable versus 1 fact table. Another method is to use prebuilt summarized data in the schema.

Classes and objects

A universe contains the following structures:• Classes

• Objects

As the universe designer, you useDesigner to create objects and classes that represent databasestructures. The objects you create in the universe must be relevant to the end user’s businessenvironment and vocabulary.

Classes

A class is a logical grouping of objects within a universe. It represents a category of objects.The name of a class should indicate the category of the objects that it contains. A class can bedivided hierarchically into subclasses.

Objects

An object is a named component that maps to data or derived data in the database. The nameof an object should be drawn from the business vocabulary of the targeted user group.

How universes are used

A universe defines the connection to the database. By selecting a universe when creating newdocuments or editing existing documents, the business users automatically receive access tothe data. The access to data, in turn, is restricted by the objects that are available in the universe.


These objects have been created by you, the universe designer, based on the needs profile fora defined user group.

Advantages of a universe

The advantages of a universe are:• Only the universe designer needs to know how to write SQL and understand the structure

of the target database.

• The interface allows you to create a universe in an easy-to-use graphical environment.

• Data is secure. Users can see only the data exposed by the universe. Users can only readdata, not edit it.

• The results are reliable and the universe is relatively easy to maintain.

• Users can use a simple interface to create reports.

• All users work with consistent business terminology.

• Users can analyze data locally.

BusinessObjects Universe Designer components

You create, modify, and update universes with Universe Designer. Designer provides aconnection wizard that allows you to connect to your database middleware. You can createmultiple connections with Designer, but only one connection can be defined for each universe.This database connection is saved with the universe.

Designer provides a graphical interface that allows you to select and view tables in a database.The database tables are represented as table symbols in a schema diagram. You can use thisinterface to manipulate tables, create joins that link the tables, create alias tables, contexts, andresolve loops in your schema. Users do not see this schema.

Designer provides an object explorer view. You use the explorer tree to create objects that mapto the columns and SQL structures that are represented in the schema view. Users select theseobjects to run queries against a database.

Starting Designer

Designer can only be usedwith a BusinessObjects repository. Youmust log onto the repositorybefore starting Designer.

After you start Designer, you can open a universe in one of the following ways:• Create a new universe.

• Import a universe from the repository.

• Open a universe directly from the file system.


A universe is available to end users once it has been exported to the repository. Importing auniverse, making changes, then exporting the updated universe to the repository is the mostcommon way of working with Designer.

Note: You can save a universe to the file system. You do this when you are in the process ofdeveloping the universe locally andwhen youwant to share the universewith other userswhomay not have connection rights to the target repository.

Note: You can lock and secure a universe before importing it fromor exporting it to the BusinessObjects Repository for maintenance.

To start Designer

1. Click the Start button on the taskbar.

2. Select the Programsmenu.

3. Select the BusinessObjects XI Release 2menu.

4. Select the BusinessObjects Enterprisemenu.

5. Select theDesignermenu.

The login dialog box for the repository appears.

Login information

name of the repository serverSystem

your repository user nameUser Name

your repository passwordPassword

authentication methodAuthentication

Note: This information is normally provided to you by the Business Objects administrator.


Note: You can also use Designer standalone. Use the authentication method Standalone(No CMS).

6. Click theOK button.

TheDesigner start-up screen appears, and an emptyDesigner session opens. The user nameand repository name appear in the title bar.

Note: Depending on options set for Designer, theQuick Design Wizard can startautomatically when you start in Designer. Click Cancel to close the wizard.

Using the Quick Design Wizard

When you start a Designer session for the first time, theQuick Design Wizard appears bydefault. You can use the wizard to quickly create a universe or to familiarize yourself withDesigner. However, unless your data source is a very simple model, it is not an appropriatetool for creating a complete universe that responds to end-user reporting requirements.

Once you are familiar with Designer, you will probably decide to disable the wizard and notuse it to design universes. All the universe design, building, maintenance information, andprocedures in this training manual are structured with the assumption that you have disabledtheQuick Design Wizard.

To deactivate the Quick Design Wizard

You can prevent the wizard from appearing automatically when you create a new universe asfollows:1. Select Tools ➤ Options. Select theGeneral tab.

2. Clear the ShowWelcome Wizard check box, and clickOK.

Note: This check box is already cleared if you have cleared the Run this wizard at startupcheck box from the Startup Wizard Welcome page.

Note: You can activate theQuick Design Wizard at any time by selecting the above checkboxes from theGeneral page of theOptions dialog box.

Using Designer module commands

There are three ways to issue commands in Designer:• Menu options

• Toolbar buttons

• Right-click menus


Menu options

You can performmost tasks by choosing options from themenu. The Designer menu bar lookslike this:

Toolbar buttons

The toolbar gives you quick access to many tasks. Designer has three toolbars: the Standardtoolbar, the Editing toolbar, and the Formula Bar toolbar.

Right-click menus

Right-clickmenus display on your screenwhen you click the rightmouse button. Thesemenususually give you access to options related to the task you are currently performing. For example,if you right-click in the Universe pane, a drop-down menu for creating classes and objects isdisplayed:

Designer window

The Designer window is made up of two segments.• On the right-hand side is the pane in which you insert the database tables and then view

the universe structure that infers the FROM and SELECT clauses into a Select statement.

This is known as the Structure pane.

• On the left-hand side is the pane in which you create the classes and objects that users willsee when they build queries using this universe. The objects physically point to the tablesyou see in the Structure pane.

This is known as the Universe pane.


Manipulating the structure view

There are threeways tomanipulate theStructurepane in theDesignerwindow: toolbar buttons,drag and drop, and by using theOptions panel.

Zoom

Often it is not possible to view the entire schema at normal magnification due to its size. Zoomin or out using the drop-down list on the toolbar to choose your percentage view for the schema.

Arrange tables

You can select this button to have Designer automatically organize your tables sequentiallyand horizontally.

Note: You can undo only the last command. If you do not like the arrange tables results, chooseUndo from the Editmenu.

Drag and Drop

Different views of the universe structure can be achieved by selecting items and applying acommand using one of the following methods:• Double-clicking

• Dragging and dropping

• Right-clicking

For example:

ActionProcedure

Click the header of the table.To mark a single table

Click it.To mark a join

Ctrl-click the header of each table (or join) youwant to highlight.To mark more than one table or join

Ctrl-A.To mark all tables and joins

Click the header of the table anddrag anddropthe table to the desired position.To move a table

By default, the table header and a specifiednumber of its columns are shown for all tables

To roll up a table contained in the universe structure segment.This view can be altered for an individual tableby double-clicking the table header.


ActionProcedure

Double-click once to roll up a table so that onlythe header is shown.Double-click twice so thatonly the table header and key columns areshown. Double-click three times to return toan unrolled view of the table.

If the view of a table does not show all thecolumns contained within that table, this isTo view the columns of a table signified by three dots at the bottom of thetable.

Click the header of the table; a scroll barappears on the right of the table. Alternatively,

To view the remaining columns

place the pointer on the bottom margin of thetable and a double-headed arrowappears. Youcan then drag the bottom margin down toexpand the number of columns shown in thetable.

To achieve this the table header must not behighlighted.

Right-click the table header and choose theView Table Values option.

To gain a partial view of the data content ofthe table

Right-click the column required and choosethe View Column Values option.

To view the data values for a single column By default, data is only displayed for the first100 rows of the table. This number can beexpanded or reduced using the Tools ➤

Options ➤ Database tab.

Right-click the table header (or structuresegment background if you want the number

To view the number of rows for a table in thedatabase

of rows for all tables) and then choose theNumber of Rows in Table option.

If you are front ending a large database, thismay not be advisable due to the time it takesto process.


Saving and exporting a universe

Regularly save your universes during a work session. When you save a universe, Designerstores it as a file with a .unv extension in your local file system. This is usually a universe folderin the BusinessObjects installation path. Any changes you have made to the universe file aresaved locally but are not propagated to the universe version in the repository until you chooseto export it.

When you export the universe, the updated version is saved on the local file system, but it iscopied to the BusinessObjects repository as well. This version is then available to end usersconnecting to the universe.

It is alsomade available to other universe designerswho are authorized by the BusinessObjectsAdministrator to access it.

Regularly save your changes to a universe locally. Then when you have finished updating theuniverse, export the latest saved version to the repository.

If you choose to browse to a copy of that universe file on your local file system and open itdirectly in Designer, the file may not be the latest version of the universe. If you want to makechanges to a universe that has already been exported to the repository, do not open a universefile directly using File➤Openmenu. Instead, use File➤ Import to ensure that you are viewingthe most recent version. Make your modifications and export your universe again to makeyour changes available in the repository.

Importing a universe

When you import a universe, you import the latest version of the universe from the repository.The universe is copied to the local file system, and this file is opened in Designer.

You can import one or more universes stored in a universe folder in the repository.

To import a universe

1. Select the Import command from the Filemenu.

The Import Universe dialog box appears.

2. Select a universe folder from the drop-down list.

Note: You can also import a universe by clicking the Browse button to select the universeyou would like to import.

Note: If you want to lock the universe, double-click the universe name. A locked universeappearswith a padlock symbol. Locking a universe prevents other designers from importingor exporting this universe. The locked universe can still be read by users and other designers.To unlock a universe, double-click it again.

3. Click the universe name.

This is the universe that you want to import.


4. Verify the file path for the import folder in the Import Folder box.

This points to the location where the universes are exported.

5. ClickOK.

Universe file names as identifiers

Do not change the universe file name after reports have been created based on that universe.If you change the file name, any report built on the universe with the old name does not pointto the universe after its name has been changed.

The universe name can be different from the .unv file name.

When you use Save As to save the universe under a new name, the new universe is notassociated in the repository. You must export the new universe to the repository to create aversion of the new universe.

You can use the following methods to save a universe:1. Select File ➤ Save from the menu bar.

2. Click the Save icon.

3. Press CTRL+S on the keyboard.

Do not save two different universes with the same file name. This leads to conflicts when youattempt to export these universes to the repository.

Saving a universe definition as a PDF

You can also save the universe information in Adobe PDF format. This allows you to save toa PDF file with the same attributes that are defined for printing purposes.

Note: You can view the default attributes by selecting the Tools ➤ Optionsmenu and selectingthe Print/PDF tab. TheOptions dialog box will be presented in detail in a later lesson.

The attributes that you can print or save to a PDF file include:• General information - parameters, linked universes, and the graphical table schema.

• Component lists - lists of components in the universe including objects, conditions,hierarchies, tables, joins, and contexts.

• Component descriptions - descriptions for the objects, conditions, hierarchies, tables, joins,and contexts in the universe.

Saving these attributes as a PDF filemay be helpful for troubleshooting ormaintenance purposes.

To save universe information as a PDF file

1. In Designer, open the universe you want to save as a PDF.

2. Select File ➤ Save As.


3. Select Portable Document Format (PDF) from the Save As type drop-down list.

4. Click Save.

Giving all users access to a universe

If you want to make a universe available to universe designers who may not have access toyour Central Management Server, you must save the universe with an unsecured connection.

To make a universe accessible to all Designer users

1. Verify that the universe that youwant tomake available to all users does not have a securedconnection.

Secured connections are required to export universes to the repository. If a universe has asecured connection, select or create a new personal or shared connection.

Note: Creating connections is discussed in detail in a later lesson.

2. Select File ➤ Save As.

3. A File Save dialog box appears.

4. Select the Save For All Users check box.

5. ClickOK.

Activity: Viewing a universe in Designer

Objective

• Open a universe and identify universe elements in Designer.

Instructions

1. Open Designer.

2. In Designer, click File ➤ Open. Browse to the eFashion.unv file found in the defaultinstallation folder:

C:\Program Files\Business Objects\BusinessObjects Enterprise

11.5\Samples\en\Universes

Or, find the same file on the Resource CD for this course.

3. Explore the menu options, toolbar buttons, and right-click drop-down menus.

4. Select View ➤ Toolbars, and ensure that all three toolbars are selected.

5. Zoom to 125% (type directly into the field instead of using the drop-down list).

6. Click View ➤ Arrange Tables to automatically organize tables.


7. Click View ➤ List Mode to list all Tables, Joins, and Contexts.

8. Click the Article_Color_Lookup table in the Tables list and to see it highlighted in thestructure below.

9. Select Tools ➤ Options and click on theGraphicsmenu tab.

10.Select the Show row count check box, and clickOK.

11.Right-click theArticle_Color_Lookup table to view the number of rows in the table (Refreshrow count for all tables).

12.Right-click the Article_Color_Lookup table to view a sample of the table values.

13.Open the Product class to view the objects it contains.

14.Double-click the Color object (notice the name, description, and select fields).

15.Select Parameters on the Filemenu and change the universe long name to New eFashion.

16.Close the universe.


The Universe Development CycleUniverse development is a cyclical process that includes planning, designing, building,distribution, andmaintenance phases. Use Designer to design and build a universe. However,the usability of any universe is directly related to how successfully the other phases in thedevelopment cycle interact with each other.


• Use the Universe Development Cycle

The Universe Development Cycle process

This unit presents an overview of a universe designing methodology that you can use to planand implement a universe development project.

The diagram below outlines the major phases in a typical Universe Development Cycle:

The analysis of user requirements and design are the most important stages in the process.Users must be heavily involved in the development process if the universe is going to fulfilltheir needs both with the business language used to name objects and the data that can beaccessed.

Implementationwill be successful if the first three stages are carried out properly. It is advisableto spend 80% of the time allocated to the development of a universe on the first three stages:• preparing

• analyzing

• planning


If you have spent the appropriate amount of time in laying the foundation for your universe,the remaining 20% of the time spent actually using Designer to build your universe will bemuch more productive.

Preparation phase

During the preparation phase, the scope of a BusinessObjects universe is defined. The productionand development architectures are identified and reviewed. Project teams are assembled andthe initial task plan is defined.

Identify universe scope

The definition and communication of project scope eliminates risk associated with deployingthe universe to pilot users during the Implementation phase. The scope is defined in terms ofintended functionality of the universe. Identification of target users of the universe also helpscreate a shared understanding of project objectives.

Key managers should be involved in the scoping process. Once formulated, the objectives ofthe project are communicated to everyone involved, directly or indirectly.

Build a project team

In designating the team members, individuals must be chosen to fill the following roles. Oneperson may fill multiple roles.

TaskRole

Usually the individual funding the project. The projectsponsor makes any final decisions regarding scope orunresolvable issues.

Sponsor

The project leader develops the project plan, assignsresources, tracks, and reports on progress.Project Leader

Individual who gathers requirements in the form ofcandidate objects.Analyst

An individual familiar with the data structures.Data Expert

Provides ongoing “business” perspective fordevelopers.Key User

Users who will work with the universe during theuniverse build and development phase.Pilot Users

An individual with BusinessObjects experience whois not part of the development process will perform atechnical review of the final product.

QA Reviewer


In most cases, a single person will be responsible for the bulk of the work, filling the roles ofAnalyst, BusinessObjects Administrator, and Data Expert.

In designing and building the universe, this person will maintain a relationship with the KeyUser, who should also be one of the Pilot Users.

This developer usually reports to a Manager or IS Director, who serves as Project Leader. TheLeader maintains a close relationship with the Sponsor.

Other roles that will be impacted by the project include theDatabaseAdministrator, the SystemAdministrator, and the Data Administrator.

Adopt standards

Standards for the components of a BusinessObjects universewill help to guarantee consistencyand stability in the final product. During preparation, the team adopts a set of standards forBusinessObjects components. Standards can be specified for:• Universe names• Object definition guidelines• Names for objects• Class names• Alias names• Help text

The standards may be revised during the course of the first universe development project asthe team becomes more familiar with the product.

Conduct a meeting

Communicate the preparation phase strategy in a meeting. This is your opportunity to gatherall interested parties (developers, users, the sponsor) to ensure that everyone understands thescope of the endeavor.

You can use thismeeting to demonstrate BusinessObjects products and to help set expectationsof the user community.

Analysis phase

The primary objective of analysis activities is to identify user requirements for the ad hoc queryenvironment.

These requirements are captured in the form of candidate classes and objects.


Identify candidate objects

There aremany places to look for candidate objects. The best way to identify them is by talkingto the end users. When interviewing end users, the type of questions to ask are: “What type ofinformation do you need to do your job?”, “How do you know you are doing well?”, “Howdoes your boss know you are performing well?”, or “What kind of information do others askyou for?”

As users answer these questions, document their answers in terms of class and objectrequirements. For example, if a user states, “We require to retrieve information on employeesby department and hire date” you have identified a potential class (“information aboutemployees”) and an object or two (“department” and “hire date”).When you identify a potentialclass, probe for objects. For example, “What kind of information about Employees do theywant?”

Candidate classes and objects can also be identified by reviewing existing reports.

Document your classes and objects. For example:

SourceDescriptionNameType

Interview #1Information on a customer, including location,credit ratings, and shipping preferences.CustomerClass

Interview #3, #4This object can be combinedwith date ranges,customers, and/or products to providemeaningful measures.

Total

RevenueObject

(Measure)

You should also try to document the qualification of objects (dimension/detail/ measure) andany potentially identified hierarchies.

Relational modeling versus multi-dimensional modeling

The questions asked during BusinessObjects interviews are similar to those asked in thedevelopment of OLTP applications. What is done with the answers is very different.

When conducting Analysis for an OLTP application, analysts document data requirements inentity relationship diagrams. Rules of normalization are applied to the items that users request,breaking them down to an atomic level, or eliminating calculated objects. These activitiesoptimize the data for storage in a relational database.

By contrast, requirements for an ad hoc query environment should be expressed in terms thatare optimized for retrieval of the information.

A successful BusinessObjects universe presents information to a business person using userspecific business terminology. The developer must “unlearn” analysis techniques used for the


development of application systems. User requirementsmust be taken at face value, remainingin business terms.

Basic rules of thumb:• Do not normalize• Do not eliminate objects that can be derived from other objects• Do not try to figure out where this data can be found in the database

For example: in an interview, a user states “I need to look at annual sales figures by region.”Document this at face value; identify the requirements, but do not attempt to transform themin a manner appropriate for storage in a relational database. You can identify three candidateobjects: “Year of Sale,” “Sales Amount,” and “Region”. Do not eliminate “Year of Sale” becauseyou have already documented a “Date of Sale” object. Do not reduce “Sales” to the componentsfromwhich it is calculated (perhaps “quantity” multiplied by “price”). Instead of normalizingobject requirements, identify how they will support on-line analysis by end users.

Identifying candidate objects as dimensions, details ormeasureswill facilitate enduser reportingand analysis flexibility. You can also plan for scope of analysis (drill-down and drill-up options)by identifying dimensional hierarchies.

Once you have gathered and documented requirements in the form of candidate objects, youare ready to begin to plan the BusinessObjects universe requirements.

Planning phase

The planning phase will be used to identify a project strategy and determine resourcerequirements.

Create a project plan

The project plan is the key to timely implementation. For each task, the plan should assignresponsibility and target dates. Creation of the plan and the tracking of progress against theplan are the primary responsibilities of the project leader.

Plan the BusinessObjects architecture

Technical architecture requirements may have been looked at in general in the preparationphase. A review of the technical architecture should take place during the planning phase ofthe project. Items to review include:

Identify resources required to support a universe developmentenvironment.

Developmentenvironment


Identify resources required for a universe production environment.Productionenvironment

Review required computing resources for developer and user workstations.Computers

Ensure infrastructure is in place to support connectivity between users/developersand the repository and data stores, including appropriate middle-ware to supportcommunication between clients and servers.

Connectivity

Identify planned configuration for client software. Ensure appropriate resources areavailable.Configuration

Initiate a first look at security requirements.Security

Develop support policy for when the universe goes into production.Support plan

Identify procedures for the request, review, approval, and implementation of changesto the universe when in production.

Change managementplan

Plan for a user training program.Training plan

Implementation phase

The implementation phase can be split up into two stages:1. Designing the schema

2. Building the universe

Implementation phase 1: schema design

The first task during schema design is to determine and document the data source for eachcandidate object. If requirements were gathered in a tabular format, add a column to the tablewhere you can indicate the SQL fragment and source tables that will be used to retrieve theobject.

SourceDescriptionSQL fragmentNameType

Interview#1

Information on a customer,including location, credit ratings,and shipping preferences.

CustomerClass


SourceDescriptionSQL fragmentNameType

Interview#3,4

This object can be combined withdate ranges, customers, and/orproducts to provide meaningfulmeasures.

SQL:sum(order_lines.quantity*products.price)

Source Tables: Order_Lines,Products

TotalRevenue

Object(Measure)

Any candidate classes that were captured as general requirements without specific objectsmust be expanded now. For example, suppose there was a candidate class called “Customer”and the specific objects within this class were not identified. During the schema design stage,the developer must “fill out” this class. The developer might fill it out based on knowledge ofthe business by including all columns from one or more tables, or the developer might go backto users for more detail.

There are several ways that objects can be mapped to enterprise data. Simple objects map backto a single column in the database. An examplewould be “Customer First Name,” whichmapsback to the First_Name column in the Customers table. Complex objects make use of SQL tomanipulate data that comes from one or more columns. For example, a Customer Full Nameobject might connect the First_Name and Last_Name columns from the Customers table.

Aggregate objects involve SQL GROUP functions. Counts, sums, and averages are all aggregateobjects. The Total Revenue object is an aggregate object; it uses the SQL SUM function.

Plan for object qualifications and drill-down functionality

As you design the universe, youmust complete the process you began during analysis. Identifyeach object as a measure, a dimension or a detail. For each detail object, identify the dimensionit is associated with.

Similarly, you need to identify hierarchies within your dimensions. These hierarchies will laterenable users to “drill-down” and “drill-up”.

Design a table diagram

Now that the objects are mapped back to data sources, the developer reviews all the objectsand produces a table-diagram of the database objects that will support the universe. Joinsbetween the tables are then added to the diagram. The table diagram is a valuable tool forresolving loops and SQL traps in the model. It will also become an important reference fordevelopers.

Note: This diagram design is usually done on paper, however this can be created directly inthe BusinessObjects Universe Designer software.

Tip: If you find that you have documented a vast amount of classes and objects based on userrequirements you may consider designing schemas that can be used to build:1. Multiple universes that cater to a specific function within the business, reducing the

complexity and amount of classes and objects.

2. Multiple universes specific to a business function, as this will prevent users from creatingqueries that can span the spectrum of the business.


Revise objects and table diagram

Once loops and SQL traps are resolved, the design of some objects will require modification.Any object based on a table that was replaced by an alias must be updated. Consult your tableof objects created in the preparation phase for such objects.

Note: If you are already usingDesigner for the schema design you can view a table’s associatedobjects to identify which objects require changes.

Some objects may be applicable in the context of more than one of the aliases; these objects willbe split intomultiple objects.Make sure that object namesmake it clearwhat each one represents.

Review join strategy

Where table relationships are optional, the type of join to use must be chosen carefully. Theuse of standard (or inner) versus outer joins will impact the results of user queries. Using thewrong type of join may provide results that are not what users expect.

In SQL, a standard join between two tables will return only rows where both tables meet thejoin criteria. If one of the tables has no corresponding row in the second table, its data will notbe returned.

An outer join tells the database processing the SQL query to substitute a “null” row if one ofthe joined tables has no corresponding row in the other table. With an outer join, informationin one table that does not have corresponding data in the second table is returnedwith “blanks”in columns from the second table.

The developer must review join possibilities with a key user wherever optional relationshipsexist. The chosen solution should produce results that users are most likely to expect.

Identify allowable object usage

The developer may identify certain objects that should not be used in qualifications by endusers. Certain complex objectsmay not be usable in qualifications for technical reasons, or theremay be performance considerations.

Determine security approach

Security requirements must also be addressed during the Implementation phase. Solutions tosecurity requirementsmay involve complex object definition, reliance ondatabase-level security,use of BusinessObjects access levels (public, private, controlled), restriction sets or thedevelopment of multiple universes. Chosen solutions may impact the database administratorand developers.

Implementation phase 2: building the universe


Once the schema design stage is complete, the development team is ready to begin using theBusinessObjects Universe Designer software to build the universe.

Tip: Remember that it is better to have several smaller less complex universes than one largeuniverse. This will reduce maintenance, avoid potential security impacts and will improveoverall usability.

Pilot users then begin to use the universe. They provide feedback to developers who refine theuniverse until build is completed.

Build the universe

The BusinessObjects Universe Designer software is used to actually build the universe. Thedeveloper must:• Name the universe• Set up the universe parameters and connect to the relevant data source• Create aliases and contexts as identified in the schema design• Create joins as identified in the schema design• Create classes, sub-classes and objects as identified in the schema design• Define objects as dimensions, details or measures• Define hierarchies• Define lists of values and help text• Define conditions and implement user security where applicable

Supply pre-built queries and reports

During the build stage, the team may identify certain queries and reports that will be of valueto the entire enterprise. Created at anytime throughout build, these queries and reports arere-checked after the universe is finalized to ensure that objects used have not been renamed orremoved. They are then exported to the repository so that they are available to all users.

Testing phase

The pilot testing and refinement phase follows universe design implementation.

Once an initial universe is built, it is deployed to the pilot users. These users work with theuniverse and provide feedback to the developers.

Types of feedback include:• Better names for classes and objects• Objects not in the universe that should be added• Objects that can be removed• Better ways to organize objects (e.g., move an object from one class to another, reclassifying

a dimension as a detail, etc.)• Objects or queries that do not behave as expected


Based on this feedback, the universe is modified. The modified universe is made available tothe pilot users for further evaluation. The testing phase can also address potential performanceissues. As a developer you can look at implementing performance enhancements to the universe.

Quality assurance

After the build is finalized, the universe is reviewed for quality assurance.

An independent reviewer makes the following checks:• Corporate standards for universe, object, class, and alias naming are followed• Objects are only definedwith tables that are referenced in the select text orWhere condition• Objects return results without syntactic error• Objects return intended business results• Objects are correctly classified as dimensions, details or measures• Defined hierarchies make sense• Objects have help text• Aliases are used appropriately• Join syntax and foreign keys are accurate• Standard and outer joins are used appropriately

These checks are best made by an individual who was not part of the development of theuniverse, guaranteeing an objective perspective. Any issues that are identified are reported tothe developers for correction and review.

Deployment phase

The universe has been built, and has passed all quality assurance checks. It is now ready fordeployment.

The final deployment of the universe cannot begin until any architectural issues identifiedduring the planning phase have been addressed. These issues include the establishment of userconnectivity, planning the installation configuration, preparation of a training program, andidentification of support and change management processes.

Architecture

Architectural considerations identified during the planning phase are reviewed. Any issuesthat have not been resolved will delay the deployment phase.

Production environment

The production environment has been set up in accordance with the architecture and securityplans identified during preparation and planning. The universe ismodified to access data from


production systems, rather than from development systems and is exported to the productionrepository.

Granting user access

Any database accounts that will be required for BusinessObjects users should be created bythe database administrator. These accounts should be given appropriate access privileges tothe data objects used by the universe.

Users are also added to the Central Management System (CMS) and granted access to theuniverse.

Conduct training

The release of the BusinessObjects universe to production users is coordinated with systemanddatabase administrators as appropriate. The user trainingprogram is executed in conjunctionwith the roll-out of the universe. Without appropriate training, users will not derive benefitsfrom BusinessObjects, regardless of the quality of the universe.

Updating/maintenance

Be sure to inform users about the support and change control mechanisms available to them.They need to knowwho to call if they have a problem or question, andwhat procedure shouldbe followed to request a change to the universe. These mechanisms were identified during theplanning phase.

Prepackaged solutions

If you are designing a universe for Business Objects developers for developing precreated/prepackaged reports, then the following items should be taken into consideration:• Predefine all filters and calculations that are used in standard documents to remain consistent

throughout• The universe can covermore than one business function to allow cross functional reporting.

Precreated reports tend to cross reference reports against different business functions. Theuniverse will therefore have to cover multiple business functions to provide end-to-endbusiness reporting.


Activity: Planning a universe

Objective

• Use the first three stages of the Universe Development Cycle.

Instructions

1. From the resource CD launch the Planning_universe_activity.html (Activity_Resources> Lesson 1) to familiarize yourself with the Universe Development Cycle and to completethe activity questions.

2. Use this checklist of questions you need to ask when you begin designing a universe:• What are the target data sources for your universes?

• What is the schema/structure of each of these data sources?

• Do you know the contents of each of the tables?

• Do you know how each of the tables are interrelated?

• Are you familiar with all of the necessary joins?

• Are you familiar with the cardinality of each of these joins?

• Have youprocureddatabase schemas from the database administratorswho administratethe data sources?

• Are you familiar with your different user populations and how they are structured?

• Do you know what standard reports are required?

• Do you know what the users' ad-hoc information needs are?

• Are you familiar with their business terminology and formats?

• Have you considered how many universes need to be created to address users' needs?

• Have you considered how long universe development may take?

• Have you considered which universes should be developed before others?

• Have you considered who should test your universes for you?

• Have you considered how data sources and/or user requirements may change overtime?

• Do you already have all of the information necessary to implement your universes?


Quiz: Understanding BusinessObjects universes1. What are the two main panes in Designer?

2. What are the three ways to issue commands in Designer?

3. Where can you define what specific information about the universe gets printed?


Lesson summaryAfter completing this lesson, you are now able to:

• Define BusinessObjects universe concepts• Use the Universe Development Cycle



Lesson 2Creating the Course Universe

Lesson introductionThis lesson introduces you to the database that is used in this course. It teaches you how tocreate a new universe and define a connection from the universe to the course database.

To create a new universe and maximize its potential, it is necessary to learn about parameters.Parameters allow you to set the structure of your universe, including setting up a databaseconnection.


• Describe the course database and universe• Create the universe

31Creating the Course Universe—Learner’s Guide

The course database and universeIn order to create a BusinessObjects universe, you must first be familiar with the data andstructure of the database to which the universe will be connected. You also need to fullyunderstand the users’ reporting requirements.


• Understand the database used during this course• Know the specifications of the universes built during this course

Course database description

During this course, you are going to build universes to report on a database for a fictional carsales and rentals organization called Prestige Motors. The database has the followingcharacteristics:• There are three showrooms, two in the US and one in the UK.

• Each showroomhas the franchise for a number of different carmakers, who allmanufacturea number of different models, available in a range of colors.

• No new models have been brought out during the period.

• Customers may either rent or buy cars.

• Customers will usually rent or buy from the showroom in their own country, but this is notalways the case.

• The database contains data for two financial years 2003/2004 and 2004/2005. Each yearbegins on April 6 and ends on April 5 in the subsequent year.

• Information about employees who work within the organization is also available in thedatabase.

• There are summary tables for quarterly and annual revenue and numbers to speed upqueries.

• The data is stored in an SQL Server database.

• Connections to the database are to be made using ODBC.

Assumptions

• There has been no inflation over the different years for which data is held.

• There is no stock data. All manufacturers are able to supply on demand.

• Users in all countries use the same currency (the US dollar).

Analysis of reporting requirements

Following an analysis of the company’s reporting needs, the following specification has beenidentified.1. Ad hoc reports are required on models.• These are required to list the cars for sale and rent.


• Such reportsmay include the following:manufacturer,model, trim, engine size, availablecolors, and sale/rental price.

• Reports may be grouped by price range and style (for example, sport, or estate).• These reportswill be used to showpotential customersmodel availability and for general

management reporting.

2. A report is required which lists the showrooms, their location and which manufacturersthey have a dealership agreement with. This report will be created by the universe designerand distributed as a corporate document for all to read and refresh.

3. Ad hoc reports are required on car sales.• These are required to list car, sale, and customer details.• Reportsmaybe grouped according to customer, showroom, sale,model, andmanufacturer

dimensions.• These reports will be used to analyze results at all levels from sales-specific details to

general high-level reports such as sales revenue per annum, per showroom, bymanufacturer, or by car.

4. Ad hoc reports are required on car rentals.• These are required to list car, rental, and customer details.• Reports may be grouped according to customer, showroom, rental, model and

manufacturer dimensions.• These reports will be used to analyze results at all levels from specific rentals details to

general high-level reports such as rentals revenue per annum, per showroom, bymanufacturer, or by car.

• Reports related to 2, 3, and 4 above will be used by sales staff, finance department staff,and managers.

Development plan

The remainder of this coursewill be spent developing universes for this imaginary deployment.In accordance with the iterative approach, the development will be phased as indicated below.1. Design and develop a universe which enables end users to build reports which meet

requirements 1 (model reporting) and 3 (sales reporting). The universe needed to do thiscan be regarded as relatively simple to create.

2. Extend the universe to meet reporting requirements 2 (franchise reporting) and 4 (rentalreporting). This requires the introduction of loops, chasm and fan traps into the universestructure which need to be resolved. This constitutes a fairly complex universe structure.

3. Further extend the universe to refine and enhance the universe for end users by introducingconditions, LOVs and hierarchies for drilling.

4. Design and develop a universe for end users that enables them to build reports which meetrequirements 5 (ad hoc reporting on employees).


Creating the universeIn this unit, you will begin to create the course universe, based on the analysis of businessrequirements and the development plan above.


• Create a new universe• Create a new data source name• Create a new connection in Designer• Describe the universe parameter settings

Creating a new universe

Before you can build a universe, you must first create a new universe file.

You save the new universe as a .unv file.

The new universe contains no classes and objects. You create these during the universedevelopment process by designing a table schema and then creating objects thatmap to databasestructures.

To begin creating a new universe

1. In Designer, selectNew from the Filemenu.

The Universe Parameters dialog box displays:


Note: Make sure the Universe Parameters dialog box displays with theDefinition tabactive.

2. In theName field, enter a name for the universe.

3. In theDescription field, enter a brief description for the universe.

This is used as a help description for the end user. It needs to accurately describe the contentof the universe using terminology the end user will easily understand.

4. Select or define the data source connection.

5. ClickOK.

6. Select File ➤ Save from the menu bar.

7. Provide a name for the file.The universe file is saved as a .unv file

Defining universe parameters

To be able to start building the universe structure, youmust first define a number of parameters,such as the parameters to be used to connect to the data source.

Universe parameters are definitions and restrictions that you define for a universe. Theseparameters:• identify the universe• identify the database connection• specify the type of queries that can be run using the universe• set the controls on the use of system resources

An important element of this setup process is selecting the kind of database connection youwill use.

Select an existing connection or create a new one. The other parameters can be set at this pointbut are better done at a later point in the universe building process.

Identifying the universe

Each universe is identified by the following parameters:

Used byIdentifier

File system, Business Objects end-userquerying tools to reference the universeFile name

Business Objects end-user querying toolsLong name

Business Objects end-user querying toolsDescription


Used byIdentifier

Central Management ServerUnique system identifier

File names

A file name is created when you save the universe. The length of the name is dependent onyour operating system maximum. Windows allows approximately 156 characters. The filename extension is .unv.

The local file system is the server on which Designer is installed. Your universes are saved bydefault in the universes folder in your user profile path as follows:

\\Documents and Settings\<user>\Application Data\Business Objects\Business Objects

11.5\universes\<universe>.unv

Note: Do not change the universe file name after reports have been created on that universeor the report files will no longer point to the universe.

Long names

The universe long name is set in the Name field on theDefinition tab. You can enter up to 200characters and there are no character restrictions.

Universe descriptions

The universe description is an optional field. Information in this field can provide useful detailsabout the universe’s role and is viewable by end users.

Unique system identifiers

The unique system identifier is assigned by the CentralManagement System (CMS). This occurswhen the universe is exported to the repository for the first time.

Setting the database connection

In order to connect to the database for which you intend to build a universe, you need to createa BusinessObjects connection.

A connection is a named set of parameters that defines how a Business Objects applicationaccesses data in a database file. A connection links Web Intelligence to your middleware. Youmust have a connection to access data.

The BusinessObjects connection contains all pertinent information for how to connect to thetarget database (for example: data access driver (middleware), connect string, connection type,and advanced connection parameters).

If you are building several universes to front end the same database, then the connection mayalready exist. Therefore, you only have to select it from the available connections. However, ifthe connection does not exist, you will have to create one.


Data access drivers

A data access driver is the software layer that connects a universe to your middleware.

Data access drivers are shipped with Business Objects products. There is a data access driverfor each supported middleware. When you install Designer, your data access key determineswhich data access drivers are installed.

When you create a new connection, you select the appropriate data access driver for the relationaldatabase management system (RDBMS) middleware that you use to connect to the targetRDBMS.

The types of databases supported through data access drivers are:• IBM DB2• Informix• Microsoft SQL Server• Oracle• Red Brick• Sybase• NRC (Teradata)• Hyperion• Generic ODBC

With the new XI architecture, connections can now be made to MS Analysis Services 2000,MySQL, and SAP. Additional connection options shown below have been added in XI R2.


ODBC connection drivers

Open Database Connectivity (ODBC) is Microsoft's strategic interface for accessing data in aheterogeneous environment of relational and non-relational database management systems.An ODBC Driver can be the "back end" for a DBMS (Database Management System) serverenvironment. Any ODBC client can access any DBMS for which there is an ODBC Driver, forexample SQL Server, Oracle, AS/400, Foxpro, Microsoft Access, or any DBMS for which anODBC driver exists.

Note: Connections to the database can bemade usingODBC aswell as OLEDB (Object Linkingand Embedding, Database). OLE DB extends the ODBC feature set to support a wider varietyof non-relational databases, such as object databases and spreadsheets that do not necessarilyimplement SQL.

To create an ODBC connection for SQL Server

Note: This example describes how to create an ODBC connection. Direct connections aresupported for certain database vendors, therefore the ODBC setup is not always required.

SQL Server is the database used for this course, and requires an ODBC connection.1. Navigate to theODBCData SourceAdministratorwizard. Use one of themethods specified

below:

• Start ➤ Programs ➤ Administrative Tools ➤ Data Sources (ODBC)

• Start ➤ Settings ➤ Control Panel ➤ Administrative Tools ➤ Data Sources (ODBC)

2. Click the System DSN tab.

3. Click Add.

4. Scroll down to select the SQL Server driver, and then click Finish.

5. In the Create a New Data Source to SQL Serverwindow add or select the following:• In theName box, type a name that identifies the database you want to connect to.• In the Server box, type (local) - unless SQL Server is installed on another machine. In

that case, select the machine name from the list.

6. ClickNext.

7. For the authentication, select the appropriate method for SQL Server to authenticate thelogin ID.Depending on the selected option, type in the requiredWindowsor SQLServer authenticationuser name and password.

8. Select theChange the default database to check box, and then select the database to connectto from the drop-down list.

9. ClickNext, and then click Finish.

10.Click Test Data Source.


You should get the message TESTS COMPLETED SUCCESSFULLY.

If you don’t get this message, review your steps and verify the added authenticationcredentials.

11.ClickOK until you can close the Administrative Toolswindow.

To define the connection in Designer

1. In the Universe Parameters dialog box, verify that theDefinition tab is selected.

2. ClickNew.

Note: You can also create a new connection from the Connections dialog box. Select Tools➤ Connections and click the Add button in the Connections list.

TheWelcome page of the Connection Wizard appears.

3. ClickNext.

TheDatabase Middleware page appears. It lists the database and middleware thatcorrespond to your data access driver key.

4. Expand the + box for the target database for the connection.

The supported middleware for that database appears in the expanded area.

5. Expand the + box for the target middleware for the connection.

The data access driver for the middleware appears.

6. Select a driver name and clickNext.The Login Parameters page appears.


To define the connection parameters

In theDefine a new connection dialog box:1. Select the connection type from the Type list box.

Note: In order to deploy a universe to the BusinessObjects repository, youmust define thisconnection type as “Secured.”

2. Define a name for the connection.

You can enter up to 35 characters.

3. In the User name and Password field enter the database login credentials.

4. In theData source name field, select the appropriate data source for the database you areconnecting to.

5. Once you have entered this information, clickNext.

More about connection types

The connection type determines who can use the connection to access data. You can createthree types of connections with Designer: personal, shared, and secured.


Personal connections

Use personal connections to restrict data access to the universe creator and the computer onwhich it was created. Using a personal connection, you have access to personal data on a localmachine.

You do not use personal connections to distribute universes.

Shared connections

Allow access to data for users. These connections are unsecured. Shared connections can beuseful in a universe testing environment.

Secured connections

Secured connections centralize and control access to data. They are the safest type of connection.Use secured connections to protect access to sensitive data.

You can create secured connections with Designer.

Connections are stored in the BusinessObjects repository. These can be shared with otherdesigners with the appropriate privileges.

You must use secured connections if you want to distribute universes through theBusinessObjects repository. Secured connections can be used and updated at any time. Todefine a secured connection you must be connected to the BusinessObjects repository.

After you have chosen your connection type and clickedNext, thePerform a test page appears.It summarizes the information for your connection and allows you to verify that the connectionis valid.

To test the new connection

1. In the Perform a test dialog box, click the Test connection button.

If the connection is valid, a message dialog box appears indicating that the connection iscorrect. If you receive an error message, check that you entered all the parameters correctly.If the error persists, refer to the section of your RDBMS documentation relating to errormessages.

2. ClickNext.


3. Set the connection time and array fetch according to the database you are using.

You can accept the default advanced settings or select from the advanced options.

The Advanced Parameters page appears.

4. ClickNext.

5. Customize the settings for listed parameters or accept the default settings.

The Custom Parameters page appears.


6. Click Finish.

If you created the connection from theUniverse Parameters dialog box, the new connectionis listed in the connection drop-down list.

Note: Avoid creating two different secured connections with the same name. For example,one connection named "Status" and the other named "status". This may lead to a conflict inthe repository.

Viewing, modifying, and deleting available connections

You can view all available stored connections in the Connections List .

Using theWizard Connection, you can edit existing connections, or create new ones.

Note: You cannot modify the name of an existing connection.

Created connections can be removed from the Connections List.

To view available connections

1. Select Tools ➤ Connections.

TheWizardConnectiondialog box appearswith theConnections Listpage. This list displaysall the connections available to the designer, regardless of the universes. The current universemay be based on a SQL Server database, but you can add a new connection to an Oracledatabase in this wizard. You can add, delete and edit existing connections from this dialogbox.


2. Click Cancel to close the dialog box.

To edit a connection

1. Click Tools ➤ Connections.

TheWizard Connection dialog box appears.

2. Select the connection that requires editing from the list of available connections.

3. Click Edit.

The Login Parameters page for the connection appears.

4. Type a new data source or database name in theData Source box if required.

5. Type modifications to login parameters as required.

6. ClickNext.

The Perform a Test page appears.

7. Click the Test Data Source button to verify the modified connection.

8. ClickNext to move to the Advanced and Custom pages. You can modify parameters asrequired. You can also accept the default or existing values.

9. Click Finish from the Custom page to apply the changes to the connection.


To delete a connection

1. Click Tools ➤ Connections.

TheWizard Connection dialog box appears.

2. Select the connection you want to delete from the list of available connections.

3. Click the Remove button.

A confirmation dialog box appears.

4. Click Yes.

The connection is removed from the list.

5. Click Finish.

Universe parameters

This topic describes the parameters that you can define using the different tabs available in theUniverse Parameters dialog box.

Note: For more detailed reference information about these parameters, refer to Chapter 2 - DoingBasic Operations, Setting Universe Parameters in the Business Objects Designer’s Guide.

Universe Parameters dialog box

There are seven tabs on theUniverse Parameters dialog box that allow you to change differentparameters. This lesson provides a brief introduction to these tabs. They are discussed in moredetail later in the course.

This table provides a quick snapshot of the different tabs:

DescriptionParameter

Universe name, description, connectionparameters, and information. Theseparametersidentify the universe.

Definition

Version and revision information, designercomments, and universe statistics.Summary

Strategies used by the universe. A strategy isa script used to extract structural informationfrom a database.

Strategies

Limitations set for the use of system resources.Controls

Types of queries that the end user is allowedto run.SQL


DescriptionParameter

Settings defined for linked universes.Links

SQL parameters that can be dynamicallyconfigured.Parameter

Definition tab

On theDefinition tab you can set the universe name and a meaningful description. There isno character limitation. End users will see these in their Business Objects querying tool whenthey select the universe.

The Connection field displays the connection name defined against the database.

Summary tab

The Summary tab displays universe administration information.


DescriptionInformation

Universe creation date and the name of thecreator.Created

Date of last modification and the name of themodifier.Modified

Revisionnumber indicates the number of timesthe universe has been exported to therepository.

Revision

Information about the universe for yourself oranother designer. This information is only

Comments

available in Designer. Includes informationabout the universe for users in theDescriptionfield on the Identification page.

You can print the text contained in this box,which means that you can use it to trackchanges made to the universe and by whom,if you so desire.

List of the number of classes, objects, tables,aliases, joins, contexts, and hierarchiescontained in the universe.

Statistics


Strategies tab

A strategy is a script that automatically extracts structural information from a database or flatfile. Default strategies have two principle roles:• Automatic join and cardinality detection

• Automatic class, object, and join creation

Strategies are useful if you want to automate the detection and creation of structures in youruniverse based on the SQL structures in the database.

Strategies that automate the creation of universe structures are not necessarily an essential partof universe design and creation. They are useful if you are creating a universe quickly, andyouwant to usemetadata information that already exists in a database or database design tool.

However, if you are building a universe by creating objects and joins that are based onrelationships that come directly from a user needs analysis, then you will probably not use theautomatic creation possibilities that this tab offers.

Built-in strategies are the default strategies that are shippedwithDesigner. You can select themby clicking the drop-downmenus in this strategies parameters tab. There are built-in strategiesfor all supported databases, which cannot be modified. You can, however, create customstrategies, which are known as external strategies. Built-in strategies appear by default beforeexternal strategies in the drop-down lists.

Note: The built-in strategies for detecting joinswill only select onmatching column names, ignoringall other column names, and may create unnecessary joins.


Controls tab

On the Controls tab, you can limit the result size and execution times for queries that use thisuniverse.

The Limit execution time option allows you to restrict the execution time for any querygenerated via the universe for queries generating more than one SQL statement.

The time limit that you specify for query execution is the total execution time for a query. Ifthe query contains multiple SQL statements, then each statement is given an execution timeequal to the total query execution time divided by the number of statements. The result is thateach statement in the query has the same execution time.

If one statement requires a lotmore time than others to run, itmay not complete as its executiontime will not correspond to its allotted execution time within the query.

When you specify an execution time limit for multiple SQL statements, you need to take intoaccount the normal execution time of the single statement that takes the longest time to run,and multiply this value by the number of statements in the query.

If you set theWarn if cost estimate exceeds option, a message informs the user if the query islikely to takemore than the number ofminutes you specify here. Thismechanism is dependenton whether the database statistics are up-to-date.

SQL tab

You can set controls on the types of queries that end users can build in BusinessObjects queryingtools.


You can indicate controls for the following areas of query generation:• Use of subqueries

• Use of operators and operands in individual queries

• Generation of multiple SQL statements

• Selection of multiple contexts

• Prevent or warn about the occurrence of a Cartesian product

Note: The Multiple SQL statements for each measure option is selected by default. Accepting thisdefault value could potentially impact query performance. This issue will be discussed in moredetail in later lessons.

Links tab

Links specify dynamic links between universes related to the same database. This allows auniverse and its content to be embedded in another universe. Embedding universes optimizesmaintenance where some objects are used in many universes.


Note: Universes need to be exported to the repository before linking.

Parameters tab

In Designer, you can configure certain SQL parameters that are common to most databases tooptimize the SQL generated. These parameters apply only to the active universe, and are savedin the .unv file.


Activity: Creating a new universe and define its connection

Objective

• Create a new universe and define its connection to the database.

Instructions

1. Create a DSN for SQL Server 2005 calledMotorsDSN.

2. Start a Designer session and log on.

3. Create a new universe and define the following parameters:• Name = Motors

• Description = This universe provides information on the Prestige Motor Cars

Database for Showrooms, Models sold, Rental and Sales Business

• Connection = Motors_conn

Tip: Use theNew Connection Wizard to create the Motors connection against the Motorsdatabase in SQL Server.

4. Save the new Motors universe .The universe is saved in the local universe directory.

5. Create another new universe and define the following parameters:• Name = Staff

• Description = This universe provides information on the personnel of Prestige

Cars.

• Connection: Motors_conn

Note: Use the same connection that you used in Step 5: that is, Motors_conn against theMotors database.

6. Save the Staff universe.


Quiz: Creating the course universe1. Information about universe administration appears on theUniverse Parametersdialog box.

Under which tab can you find this information?

2. Can a universe and its content be embedded in another universe?

3. If you want to distribute the completed universe to the user population using theBusinessObjects repository, which type of connection should you use?



• Describe the course database and universe• Create the universe


Lesson 3Building the Universe Structure

Lesson introductionThis lesson describes how to add tables to the universe structure and how to customize theway you work with tables.


• Populate the universe structure• Define joins in a universe

55Building the Universe Structure—Learner’s Guide

Populating the universe structureA schema is a graphical representation of a database structure. InDesigner you create a schemafor the part of the database that your universe represents.


• Design a schema

• Add tables in the Structure pane

• Organize your view of tables

Designing a schema

The schema contains tables and joins. Objects are mapped to columns in tables that end usersuse to create reports. The joins link the tables so that the correct data is returned for queriesthat are run on multiple tables.

Design the schema in the Structure pane by selecting tables from the target database using theTable Browser. You create joins to link the tables. When you have designed the schema foryour universe, you can verify the schema using an automatic integrity check.

Good schema design is essential to good universe design. Populate the schema with tablesbased on the columns that correspond to the objects that end users need to create reports. Definethe objects according to a needs analysis. Examine the database for tables that allow you tocreate these necessary objects.

Schema design and the universe creation process

After the initial schema design in the first implementation phase of the Universe DevelopmentCycle, you will start using Designer to build your universe.

Adding tables

The Structure pane of the Designer interface is used to create a visual representation of thephysical data structure to which the universe is mapped. When you create a new universe, thestructure is empty and you need to populate it with the appropriate tables. Database tables areplaced in the structure using theTable Browser, which provides a list of tables in the database.

TheTable Browser is an independentwindow that shows a tree viewof the tables and columnsin your target database. Use the Table Browser to view and select tables in your database that


you want to insert into your schema. Expand the + box next to a table name to display thecolumns for the table.

To open the Table Browser

The Table Browser is not visible by default. You must activate the Table Browserwhen youwant to add tables to the Structure pane. You can activate the Table Browser using any of themethods listed below.

Note: A universe file has to be open in Designer to be able to access the Table Browser.

1. You can open the Table Browser using one of the following methods:

• Click the Table Browser button on the Editing toolbar.• Double-click the background area of the Structure pane.• Select Insert ➤ Tables from the menu bar.• Right-click the Structure pane and choose Tables from the drop-down menu.

The Table Browser displays:

From the Table Browser you can select tables to include in the universe schema. You caninsert a single table or multiple tables simultaneously.

To insert a single table

1. You can use the following methods to insert a single table:


• In the Table Browser, click a table and drag it into the Structure pane.• In the Table Browser double-click a table.• In the Table Browser click a table, and click Insert.

The table appears in the Structure pane.

To insert multiple tables

1. In theTable Browser, hold the Shift keywhile you click the first table and last table to selecta continuous block of tables. Multiple tables are selected.

Note: The Ctrl key can also be used here to select multiple tables.

Tip: It is a good practice to insert only a few tables together at one time. This makes theschema more manageable when making further adjustments and adding joins.

2. Use one of the following methods to add the tables to the Structure pane:

• Click Insert• Drag and drop the selected tables in the Structure pane.

Each table including all of its columns appears in the Structure pane. In the Table Browser,any table that you insert in the universe displays with a check mark beside its name.

Note: Columns cannot be selectively chosen. When you select a table, all columns will beincluded in the structure.

To view data from the Table Browser

You can use theTable Browser to view the data contained in a table, or in an individual column.1. Expand a table +box in the Table Browser and right-click a column or the entire table.

2. Select View Table Values from the pop-up menu.

A dialog box appears listing the data contained in the table or column.


Manipulating tables in the universe structure

When a table has been placed in the Structure pane, it shows the names of the columns itcontains.

You can use various commands to manipulate tables within the Structure pane. These aredescribed in the sections that follow.

You can move, copy, or delete tables in the Structure pane, as well as organize and change thetable display.

To select tables

Usually the first step in moving, copying, or deleting tables is to select them.1. To select a single table, click the table header.

2. To select several tables, pressCtrl and click the table header of each table youwant to selectin turn.

3. To select all tables, press Ctrl + A or choose Edit ➤ Select All from the menu bar.

Tip: You can also select multiple tables by:

• clicking on the Structure pane• holding the left mouse button down• dragging the mouse across the tables you want to select

A line appears when you do this and boxes in your selection.


4. To deselect a table, click the background of the Structure pane.

To move tables

1. Select the tables you want to move.

2. Drag the tables to a new position.

To delete tables

1. Select the tables you want to delete.

2. Press theDelete key.

To organize your tables

There are several options that enable you to obtain a better view of your tables:1. Use drag and drop to move the tables around the Structure pane.

2. Click the Arrange Tables button to arrange tables horizontally.

3. Select from the Zoom drop-down list to minimize or magnify the Structure pane.

4. Double-click the table header in Structure pane to change the table display.


To change a table display

You can change tables so that they display all columns of a table, the table name only, or theprimary and secondary keys (join columns) only.1. There are three options to change a table display:

• Select View ➤ Change Table Display from the menu bar.• Select Ctrl + T.• Double-click the table header.

Table name displays:

2. If you select View ➤ Change Table Display , Ctrl+T, or double-click a second time, onlythe Join columns will display in the table.

Join columns only display:

If you repeat one of those actions a third time, the original table view appears again.

To view table values

You can view the data for a database table or column in the sameway as in the Table Browser.1. Right-click the header of the table whose values you want to see.

The following menu displays:


2. From the menu, choose Table Values.

3. Click Close.

Activity: Populating the universe structure

Objective

• Insert tables into the Motors universe.

Instructions

1. Insert the tables listed below into your blank Motors universe.• CLIENT


• COLOUR• COUNTRY• FINANCE_PERIOD• MAKER• MODEL• REGION• SALE• SALES_PRICE_RANGE• SALE_MODEL• SHOWROOM• STYLE

2. Order the tables so that they are laid out in the same way as the illustration below.

3. Save the changes to the universe.


Defining joins in a universeAfter you have inserted more than one table in the schema, you need to create joins betweenrelated tables. A join is a condition that restricts the resultset of a multi-relational query. Joinsare as important as tables in a schema because they allow you to combine data from multipletables in a meaningful way.


• Understand why you need joins in the universe structure• Create joins• Set join cardinalities• Explain the join types• View join expressions using List Mode• Check the integrity of the universe structure and its joins

About joins and SQL WHERE clauses

SQL specifies a join implicitly in a WHERE clause through a reference to thematching or commoncolumns of the tables. Normally there is one WHERE clause for each pair of tables being joined.For example, if four tables are being combined, three WHERE conditions are necessary.

In BusinessObjects querying tools, if you run a query that involves inferring a SELECT statementon two tables that have not been joined in the universe structure, the resulting report producesa Cartesian product, that is, an illogical question resulting in illogical data, as illustrated below.In other words, it outputs a report that joins every column in the first table to every column inthe second table.

To prevent this from happening, you need to specify a join between the tables in the Structurepane in Designer.


Creating joins

You have several approaches to creating joins in Designer:• Defining joins manually in the schema

• Defining join properties directly in the Edit Join dialog box

• Using the Join SQL Editor to specify the join expression

Each of these approaches is described in detail below.

Defining joins manually in the schema

You can graphically create individual joins between tables by using the mouse to drag a linefrom a column in one table to a matching column in another table.

Creating the join by defining properties

You can also create a join by directly defining the join properties in the Edit Join dialog box.

To create a join by tracing manually

1. Click on any blank area of the Structure pane to deselect all tables.

2. Position the pointer over a column that you want to be one end of a join.

The pointer appears as a hand symbol.

3. Click and hold down the left mouse button.

The column is highlighted.

4. Drag the mouse to the column in another table that you want to be the other end of the join.

As you drag, the pointer changes into a pencil symbol.

5. Position the pencil symbol over the target column.

The target column is highlighted.

6. Release the mouse button.

The join between the two tables is created. Note that the definition of the join appears in theFormula toolbar.

7. Double-click the new join.

The Edit Join dialog box appears showing the join properties.


Note: The properties that you can set for a join, including cardinality and join type, aredescribed later in this lesson. The Edit Join dialog box displays the default properties of thejoin.

8. Enter and select properties for the join.

9. ClickOK to close the Edit Join dialog box.

To create a join using the Edit Join dialog box

1. Select Insert ➤ Join from the menu, or click the Insert join button.

The Edit Join dialog box appears.

2. Select a table from the Table1 drop-down list.

The columns for the selected table appear in the list box under the table name.

3. Click the name of the column that you want to be at one end of the new join.

4. Select a table from the Table2 drop-down list box.

The columns for the selected table appear in the list box under the table name.

5. Click the name of the column that you want to be at the other end of the new join.

The join expression is dynamically built in the zones below and can bemodified as necessary.

Note: The properties that you can set for this join, including the join operator, cardinality,and join type are described later in this lesson.


6. ClickOK.

The new join appears in the schema, linking the two tables and columns that you specifiedin the Edit Join dialog box.

Note: Another method for inserting a join is to click the first table in the Structure pane,hold down the Ctrl key, click the other table, and then click Insert Join. The two tables areautomatically entered in the Edit Join box and you can edit the join properties as required.

About join properties

You can define the following properties for a join.

DescriptionProperty

Table at the left end of the join. Columns are listed forthe table selected in the drop-down list.Table1

Table at the right side of the join. Columns are listedfor the table selected in the drop-down list.Table2

Operator that defines how the tables are joined. Theoperators available to a join are described in thefollowing section.

Operator

When selected, determines which table containsunmatched data in an outer join relationship. Outerjoins are described fully in the following section.

Outer Join

When selected, allows you to define the cardinalityfor the join. Defining and using cardinalities isdescribed in the following section.

Cardinality

Defines the join as a shortcut join. Shortcut joins aredescribed in the following section.Shortcut Join

WHERE clause used to restrict the data that is returnedwhen the two joined tables are included in a query.This clause can be edited as necessary.

Expression

Join operators

You can select an operator for a join from the drop-down list between the Table1 and Table2boxes. The operator allows you to define the restriction that the join uses tomatch data betweenthe joined columns.

You can select the following operators for a join:

DescriptionOperator

equal to=

not equal to!=


DescriptionOperator

greater than>

less than<

greater than or equal to>=

less than or equal to<=

between (theta joins)Between

complex relationshipComplex

Editing the join expression

Use the Edit Join dialog box to define and edit join properties. You can also access the Join SQLeditor to edit join syntax directly from this dialog box.

The Edit Join dialog box also has two features available that allow you to edit and verify thejoin syntax:

Edit

The Edit button opens an SQL editor. Use this graphic editor to modify the syntax for tables,columns, operators, and functions used in the join.

Parse

The Parse button starts a parsing function that verifies the SQL syntax of the join expression.If the parse is successful, you receive a result is OK message. If Designer encounters an error,you receive an error message indicating the source of the problem.

Using the Join SQL editor

You can use a graphical editor to directly modify the SQL expression for a join. You access thiseditor from the Edit Join dialog box by clicking the Edit button.

To modify a join using the Join SQL editor

1. Double-click a join in the Structure pane, or click a join and select Edit ➤ Join.


2. Below the Expression text box, click the Edit... button.


The Join SQL Definition dialog box appears. The SQL expression for the join appears inthe text box.

3. Modify the SQL syntax as required.

You can use the following editing features to modify or add SQL syntax:

Then...If you want to...

Expand the table + box in the Tables and Columnsbox and double-click on a new column name.

Change a column at either join end

Double-click an operator in the Operators box.Change an operator used by the join

Expand a function family + box and double-click ona new function, or edit the SQL text directly.

Use a function in the join

The column, operator, or function appears in the join definition.

4. ClickOK to validate your changes.

5. Verify that the join expression in the Expression text box has been modified.

6. ClickOK to close the Edit Join dialog box.

Detecting joins

Joins can also be created automatically. This procedure can be applied to multiple tables or, ifnone are selected, all tables in the Structure pane.


Note: The automatic detection of joins assumes that all columns with matching names are to bejoined, and other columns will be ignored. This may not be appropriate, in which case it is betterto insert the joins manually.

To detect joins automatically

1. Click the table you want to select joins for.

Note:

You can select multiple tables by pressing the Shift key, and clicking each table. You canalso select all tables in a zone by clicking in an empty space, and dragging the cursor todefine a rectangular zone that includes any number of tables.

2. To detect the joins automatically:

• Select Tools ➤ Automated Detection ➤ Detect Joins.• Click theDetect Joins button from the Editing toolbar.

A Candidate Joins dialog box displays listing all the joins detected.

3. Click the join or joins you want to accept in the Candidate Joins dialog box.

Note: You can accept and insert several joins at the same time using Shift-click or Ctrl-click.

4. Click Insert.

The join or joins are inserted in the Structure pane.

5. Click Close.

Setting join cardinalities

Setting cardinality is a critical step in universe development. Cardinality is the term that refersto the relationship between two tables based on a join, specifically howmany rows in one tablewill match those in the other. Whether or not cardinality is defined or how it is defined doesnot directly impact the SQL that is inferred in universe queries. Rather, a universe designerdefines cardinality to benefit from powerful assistance from the Designer resolving-loops tool.

About cardinality

Cardinality is the means by which Designer identifies the relationships between tables in theuniverse structure. The cardinality can be:• one-to-one (1-1)

• one-to-many (1-N)

• many-to-one (–1)

• many-to-many (N-N)


For example, a country can have many regions, so the relationship between a Country and aRegion table is 1-N.

Designer uses cardinality to detect and resolve loops.

Note: It is very important that all cardinalities are set correctly for loop and context detection. Thiswill be discussed in more detail later in this course.

You can choose to set cardinality manually or by using an automatic detection tool.

Setting cardinality manually or with the automatic detection tool

Cardinality in universe design is based on a logical algorithm using a physical count. Theautomatic detection tool only works properly if the database is populated with realistic datain a completely normalized structure (for example, no multiple lookup tables or other tricksthat are sometimes applied by database administrators).

Also, it is important to understand that because the detection tool runs three queries on everyjoin, it can take a long time to complete the detection method. The cardinality detection toolworks by running the following queries:• A count of the rows in each of the two tables that are joined (two queries)

• A count of the rows outputwhen applying a querywith the join specified in the WHERE clause(one query)

For these reasons, you are strongly advised to apply cardinality manually for efficiency andaccuracy.

When you set cardinalities manually, you must consider each individual join. This helps youto become aware of potential join path problems in your schema.

You may not find these problems if you only select automatically detected cardinalities; forexample, isolated one-to-one joins at the end of a join path, or excessive primary keys wherenot all columns are required to ensure uniqueness.

To set cardinality manually

It is recommended that you systematically set the join cardinality when you first create a join,using the following manual method.1. Double-click a join, or click a join and select Edit ➤ Properties.

The Edit Join dialog box appears with the join expression already defined. In the center ofthe dialog box is the Cardinality zone.


2. To set the cardinality manually, click the appropriate 1 andN option buttons in theCardinality zone.

Note: 1 = one end of join; N = Many end of join.

Tip: As you click the different options in the Cardinality zone, a message appears belowthe buttons to describe the relationship between the tables, based on the settings you select.

3. Select the 1 orN radio button for Table1.

4. Select the 1 orN radio button for Table2.


5. ClickOK to accept your changes and close the Edit Join dialog box.

Displaying cardinalities

You can display cardinalities in the Structure pane using the following symbols:

DescriptionExampleCardinality symbol

Arrow indicates the “one”directionof the join. If cardinality is 1,1 thenArrow an arrow head is shown at each joinend.

Crow’s foot indicates the “many”end of the join. If cardinality is 1,1,then a straight line is shown.

Arity


DescriptionExampleCardinality symbol

Cardinality is shown as a ratio ateach end of the join.1,N

To display cardinalities

1. Select Tools ➤ Options from the menu bar.

2. TheOptions dialog box opens to theGeneral page.

3. Click theGraphics tab.TheGraphics page appears.

4. Select the Arrow, Arity, or 1,n option.

5. ClickOK to save the changes.


Detecting cardinality automatically

You can set Designer to detect cardinality automatically as you insert joins, however it isrecommended that you use themanualmethoddescribed previously, to ensure accurate results.

You can detect cardinality for a single join by selecting that join and clicking theDetectCardinalities icon in the Editing toolbar. This is due to the fact that, if the database is large,running the cardinality detection queries for every join can take considerable time.

How is cardinality detected?

To detect the cardinality of a join between two tables, the following three queries are run:SELECT count (*)FROM table1, table2WHERE table1.column = table2.columnSELECT count (*)FROM table1SELECT count (*)FROM table2.

The results of the three queries are then compared in an attempt to determine which query isthe end of the join with one entity and which is the end with many (if there is one).

To detect cardinality on a single join

Cardinality can be detected on a single join using one of two methods.1. Using the Edit Join dialog box:

a. Double-click the join in the Structure pane to open the Edit Join dialog box.b. In the Cardinality zone of the Edit Join dialog box, click theDetect button.c. Check the cardinality statement tomake sure that the one-to-many relationship proposed

makes logical sense.d. ClickOK to accept the proposed cardinality and close the Edit Join dialog box.

In the Structure pane, Designer applies the cardinality symbol to the appropriate end ofthe join, based on the cardinality proposed by the detection tool.

2. Using theDetect Cardinality button:a. Select the join.b. Click theDetect Cardinalities button.

The automatic tool detects the cardinality of the join and applies the arity symbol to theappropriate end of the join.

c. Check the arity symbols displayed between the tables tomake sure that the one-to-manyrelationship proposed makes logical sense.

d. Edit the cardinality proposed in the Edit Join dialog box if necessary.


Detect cardinality for all joins

You can use the Designer featureDetect Cardinalities to automatically detect all joins in theschema.

When using automatic cardinality detection, cardinalities are implemented automatically ondetection.

You should use automatic cardinality detection appropriately. It can be very useful to quicklyget all the cardinalities detected in the schema, however, there are a number of structuralproblems inherent inmany relational databaseswhich can lead to incorrect cardinality detection.

To detect cardinality for all joins

You can also detect cardinality all at the same time, although this is not a recommendedprocedure to ensure accurate results.1. Click the Structure pane background to ensure no join is selected.

2. Click theDetect Cardinality button on the toolbar.

Note: Cardinality is detected by automatically running three subsequent queries at thetarget database per join. You are therefore advised to avoid automatic detection ofcardinalities on large databases. Use the manual method whenever cardinality is known.

A message appears.

Designer requests confirmation because executing the detection tool takes a long time if itis being applied to a large database.

3. If you are sure you want to use the automatic detection tool, clickOK to detect thecardinalities.

The system inserts the cardinality symbols on the many ends of the joins.


Designer offers yet another method for detecting cardinalities automatically:1. Select Tools ➤ Options from the menu bar.

2. Click theDatabase tab.

3. Select theDetect cardinalities in joins check box.

4. ClickOK.

Best practice for setting join cardinality

As mentioned previously, there are three reasons why using the automatic detection tool toset join cardinalities is not recommended:• Cardinality is based on logic. It is logical that every country has more than one region; it is

not logical that a regionmay havemore than one country. The automatic detection tool usesphysical cardinality, and runs a physical count on the values in both columns being joined.Youmay get incorrect results if the physical count does not return the same result as a logicalanalysis of the data.

• The algorithmused by the automatic detection tool assumes that you have sufficient quantityof data in both tables to be representative in ratio to the database in a live environment. Ifyou are designing against a test database, for example, with only a representative samplingof data, you could receive an incorrect answer because the tool runs a physical count.

• The automatic detection tool runs three subsequent queries against the target database perjoin. You are therefore advised to avoid automatic detection of cardinalities on largedatabases.


Join types

DescriptionJoin Type

Link tables based on the equality between the valuesin the column of one table and the values in the

Equi-join (default) (includes the complex equi-join)columnof another. Because the same column is presentin both tables, the join synchronizes the two tables.You can also create complex equi-joins, where one joinlinks multiple columns between two tables. Equi-joinis the join type created by default between two tables.

Link two tables, one of which has rows that may notmatch those in the common column of the other table.Outer join

Link tables based on a relationship other than equalitybetween two columns, as in for example, a BETWEENjoin.

Theta join (conditional join)

Join providing an alternate path between two tables,bypassing intermediate tables, leading to the sameShortcut join result regardless of direction. Optimizes query timeby cutting long join paths as short as possible.

Single-table join used to set a restriction on the table.Self-restricting join

Equi-joins

An equi-join is a restriction that conforms to the syntax set out below:Table1.column_a = Table2.column_a

An equi-join is a join based on column values between two tables. In a normalized database,the columns used in an equi-join are often the primary key from one table and the foreign keyin the other. A primary key of a relational table uniquely identifies each record in the table.Primary keys may consist of a single attribute or multiple attributes in combination. A foreignkey is a field in a relational table that matches the primary key column of another table.

When a SELECT statement is run, the SELECT and FROM clauses are now properly defined andprevent a Cartesian product.


Outer joins

An outer join is a join that links two tables, one of which has rows that may not match thosein the common column of the other table.

You define an outer join by specifying which table is the outer table in the original equi-join.The outer table contains the column for which you want to return all values, even if they areunmatched. You specify the outer table from the Edit Join dialog box for the selected join.

For instance, the example illustrated above shows the Country and Region tables from adatabase. Note that there are three different values in the primary key of the Country table andonly two distinct values in the corresponding foreign key of the Region table. If you were toapply an equi-join, the resultset of a query would only show information on US and UK.However, you may wish to show all three countries irrespective of equivalent foreign keyvalues in the Region table. To achieve this, use an outer join.

In specifying an outer join in a standard SQL SELECT statement, you are required to identifywhich of the two tables is the outer. Using straight SQL (as opposed to generating it using auniverse), the problem is that different RDBMS define outer differently and the syntax of thestatement also differs. For example, depending on the underlying RDBMS, the outer join maybe on the left or right.

In a universe, the outer join is always placed on the table that contains all the data. That is, onCountry in the example above. To do this, place a check against that table in the Edit Join dialogbox.

Tip: A goodway to find out where to place your outer join is by reading the description that showsup in the Cardinality zone. If you select the outer join check box for Country the description reads:

Each Country has ZERO or more Regions, AND each Region has one and only one Country.

When you check the outer join box for theCountry table, youwill retrieve all countrieswhetherthey have a region or not.


Once this is done, the correct outer join is inferred when used in the generated query, and thesyntax is correctly inferred for the appropriate RDBMS (assuming you have the correct SQLinference driver).

An outer join is shown by a small circle on the join line in the universe structure at the end thatpoints to the table that may have missing values.

Best Practice with Outer Joins

It is recommended that outer joins be placed at the end of the flow of data, otherwise ambiguousouter join errorsmay occur. Potentially, this could cause the SQL to try tomatch on the equalityof a NULL value, which it cannot do.

If you do place outer joins in the middle of a table path, the subsequent joins in the path mayalso have to be made outer to avoid errors.

Always remember that outer joins may cause the query to run slower than a query with noouter joins.

This problem can be resolved by using aliases and aggregate aware.

Theta joins

A theta join is a “between-type” join that links tables based on a relationship other than equalitybetween two columns. It is used to demonstrate ranges, such as start date and end date, orminimum and maximum. A theta join can use any operator other than the equal operator.


For instance, there is a table in the Motors database called Sales_Price_Range. This contains anumber of rows defining fixed price ranges bywhich youmaywish to analyze data as illustratedabove.

To do this, the table needs to be included in the universe structure and a join set. The obvioustable to join it to is the Model table which includes the price of a model. However, there is nocommon column between the Sales_Price_Range and Model tables so an equi-join cannot beused. Instead you need to infer that a join exists where the value in a row of the Model_Pricecolumn in the Model table is between the values in a row for the Price_Range_Min andPrice_Range_Max columns of the Sales_Price_Range table.

To create a theta joinTo create a theta join using range columns:1. Click the Insert Join button, or select Insert ➤ Join.


2. Select a table from the Table1 drop-down list.

The columns for the selected table appear in the list under the table name.

3. Click the column you want to join.

4. Select the a table from the Table2 drop-down list.


5. Press and hold down the Ctrl key and click two columns from the Table2 column list box.


Note: The operand changes to Between automatically, and indicates that the join expressionis dynamically built as a Between syntax.

6. Click the Parse button to test for the validity of the join.If you receive an error message, check to see that you have correctly selected the columns.

7. Set the correct cardinality.

8. ClickOK.

The theta join now appears between the two selected tables.

Shortcut joins

A common use of shortcut joins is to link a shared lookup table to another table further alonga join path. The join path is comprised of several different tables in the same context.

A shortcut join is a join that provides an alternate path between two tables. It improves theperformance of a query by not taking into account intermediate tables, and shortening a normallylonger join path.

In such a case, the shortcut join is only effective when the value being looked up has beendenormalized to lower levels in a hierarchy of tables so the same value exists at all the levelsbeing joined.

In the Motors sample database you can apply a shortcut join from the Country table to theClient table, bypassing the Region table. As there is already a join betweenCountry andRegion,


adding a new join between Country and Client will effectively create a loop. You can avoidand solve this loop by using a shortcut join.

To create a shortcut join

1. Identify the two tables in a join path that can be linked directly.

2. Create a join between the two tables.

3. Double-click the new join.


4. Set the correct cardinality.

5. Select the Shortcut Join option.

Note: Note that this will not change anything in the operands or the expression field.

6. ClickOK.

The shortcut join now appears as a dotted line between the two selected tables.

Self-restricting joins

A self-restricting join is not really a join at all, but a self-restriction on a single table, usually atransaction table. You can use a self-restricting join to restrict the results returned by a tableusing a fixed value.


The table in the example above contains rows of data for cars both sold and rented. The saletype column is used as a flag to indicate the type of transaction. Without the self-restrictingjoin, the results set of the query would produce rows where the sale type column is equal toeither car sales ('S') or car rental ('R'). With the self-restricting join expression set to sale typeequal to ‘S’, any object based on the table or joins passing through that table would producequery results covering only car sales.

To create a self-restricting join

1. Use one of the following methods to insert a join:

• Click the Insert Join button.• Select Insert ➤ Join.


2. Select the table from the Table1 drop-down list.

Select the table that you want to set the self restricting join against from the Table1 drop-down list box.


3. Click the column that you want to use to define the restriction from the column drop-downlist box.

4. From the Table2 drop-down list, select the same table that you selected from the Table1drop-down list box.

5. Click the same column that you selected in the Table1 column list box.The expression for the join appears in the Expression text box.

6. Replace the operand value in the join expression with the restriction value that you wantto set on the join column.

For example, if you want to restrict the returned values from the sale type column to carsales values only, you replace SALE_TYPE after the = sign with 'S' as shown below:

Tip: This can also be done directly in the Expression field.


Note: It is recommend that you set the cardinality of a self-restricting join to 1:1. Otherwise,when running detect contexts, you will get an error that not all cardinalities have beendetected.

7. ClickOK

The self-restricting join now appears as an unconnected join line.

You can view the join expression underlying a join line or all the join expressions for a tableusing List Mode as well as the Edit Joins dialog box.

List Mode

You can use List Mode to list the tables, joins, and contexts used in the active universe. In ListMode, Designer adds three panes above the display of the Structure pane; tables, joins, and


contexts. You can view the join expression underlying a join line or all join expressions for atable using List Mode as well as the Edit Joins dialog box.

To use List Mode

1. Click the View List Mode button.

After ListMode opens, you can view tables and join information and expressions in variousways. For example:

2. Click a join in the graphical Structure pane.

The expression for the join is highlighted in the Joins pane in the List Mode.

3. Click a table in theTables pane of ListMode, and click the arrowpointing to the Joins pane.

Only the joins for the selected table are shown in the Joins pane.

4. Clear the highlighted arrow to view all the joins and tables again.

5. Click the View List Mode button to return to normal view.

Note: Make sure you clear any arrows in ListMode before returning to normal view. The restrictedview of tables could interfere with operations that you perform in normal view, such as detectingcontexts.


Checking integrity

Use the Check Integrity option to detect any errors in the structure and joins of a universe.

Be careful of checking cardinality automatically for all the reasons mentioned previously. Asa general rule, never select the Check Cardinalities check box when you are checking theintegrity of your universe.

To check the integrity of a universe

1. Click the Check Integrity button.

The Integrity Check dialog box displays:

2. Select check boxes for components to be verified.

3. Clear check boxes for components not to be verified

4. ClickOK.Designer checks the universe and displays the Integrity Check Results dialog box.If there are no errors, clickOK. Otherwise, you need to return to your Structure pane andcorrect any errors as indicated in the Integrity Check Results dialog box.

Note: Some divergences in integrity results are acceptable.

Activity: Defining joins in a universe

Objective

• Insert joins between tables in the Motors universe and set cardinalities.

Instructions

1. Insert the following equi-join using the drag-and-drop technique:


• COUNTRY.COUNTRY_ID to REGION.COUNTRY_ID

2. Set the cardinality for the join manually in the Edit Join dialog box.

3. Insert the following equi-join using the Edit Join dialog box and set the cardinality.• REGION.REGION_ID to CLIENT.REGION_ID

4. Insert the following theta join and set cardinality.• MODEL.MODEL_PRICE BETWEEN SALE_PRICE_RANGE.PRICE_RANGE_MIN AND

SALE_PRICE_RANGE.PRICE_RANGE_MAX

5. Insert the following self-restricting join and set cardinality.• SALE.SALE_TYPE='S'

6. Check integrity for:• Universe structure and joins

7. Notice the divergences found in the integrity check of theMotors universe. This is the resultof having un-joined tables.


8. Check that the following joins and cardinalities are included in the universe structure. Ifnot, add the remaining joins and cardinalities as specified in the table below:

CardinalityTypeJoins

1:NEquiCOUNTRY.COUNTRY_ID = REGION.COUNTRY_ID

1:NEquiREGION.REGION_ID = CLIENT.REGION_ID

N:1ThetaMODEL.MODEL_PRICE BETWEEN SALE_PRICE_RANGE.PRICE_RANGE_MIN ANDSALE_PRICE_RANGE.PRICE_RANGE_MAX

1:NSelfSALE.SALE_TYPE = 'S'

1:NEquiCLIENT.CLIENT_ID = SALE.CLIENT_ID

1:NEquiSHOWROOM.SHOWROOM_ID = SALE.SHOWROOM_ID

N:1EquiSALE_MODEL.MODEL_ID = MODEL.MODEL_ID

N:1EquiMODEL.STYLE_ID = STYLE.STYLE_ID

N:1EquiMODEL.MAKER_ID = MAKER.MAKER_ID

N:1EquiSALE_MODEL.COLOUR_ID = COLOUR.COLOUR_ID

N:1ThetaSALE.SALE_DATE BETWEEN FINANCE_PERIOD.FP_START ANDFINANCE_PERIOD.FP_END

1:NEquiSALE.SALE_ID = SALE_MODEL.SALE_ID

9. Save the changes to the universe.


Quiz: Building the universe structure1. A schema contains two elements. What are they?

2. What are three reasonswhyusing the automatic detection routine for setting join cardinalitiesis not recommended?

3. What type of join is created by default between two tables?



• Populate the universe structure• Define joins in a universe



Lesson 4Creating Dimension Objects

Lesson introductionThis lesson describes how you can create classes and objects that are used by end users to runqueries and create reports.


• Describe classes and objects• Create classes and objects

93Creating Dimension Objects—Learner’s Guide

Classes and objectsBecause universes are made up of objects and classes, it is important to understand exactlyhow each of these elements is used.


• Explain what universe objects are

• Explain what universe classes are

Classes

Within a universe, objects are grouped into classes. This is done to provide a structure for theuniverse and makes it easier for users to locate particular objects. The strategy most oftenemployed is to group related dimension and detail objects into one class and place measureobjects into a unique and single-measures class.

This strategy can be extended by introducing subclasses to break down the objects into furthersubsets.

Each object in a universe must be contained within a class. You can create new classes and editthe properties of existing classes. Classes are represented as folders on a tree hierarchy in theUniverse pane.

In Designer, you can qualify an object as being one of three types:

DescriptionExamplesObject qualification

Focus of analysis in a query. Adimension maps to one or

Dimension more columns or functions inthe database that are key to aquery.

Provides descriptive dataabout a dimension. A detail is

Detail

always attached to adimension. It maps to one ormore columns or functions inthe database that providedetailed information related toa dimension.


DescriptionExamplesObject qualification

Contains aggregate functionsthat map to statistics in the

Measure database. These are themetricsbywhich youwant to comparedimensions.

Dimension objects, where possible, tend to be organized hierarchically within a class. This isimportant if you intend to make use of default hierarchies for drilling. Detail objects areorganized below their associated dimension objects.

Note: Detail objects cannot be included in a drill path.

Measure objects may be grouped in a separate class. This makes them easier for the user tofind and also emphasizes the fact that they can be used with any dimension or detail object.

Note: Only dimension objects can be merged to synchronize queries frommultiple data sources inend-user querying tools.

Objects

In Business Objects products, an object is a named component in a universe that represents acolumn or function in a database.

In Designer, objects appear as icons in the Universe pane. Each object represents a meaningfulentity, fact, or calculation used in an end user’s business environment. The objects that youcreate in theUniverse pane inDesigner are the objects that end users see and use in the BusinessObjects end-user querying tools.

In theWeb Intelligence Java Report Panel, users drag objects from theData tab into theResultObjects pane to run queries and create reports that display the data returned by the query.

Each object maps to a column or function in the target database, and when an object is selectedin theWeb Intelligence Java or HTML report panel, the object infers a SELECT statement. Whenmultiple objects are combined, a SELECT statement is run on the database which includes theSQL inferred by each object and a default WHERE clause.


As a universe designer, you use Designer to create the objects that end users select to build andrun their queries.

You can also create objects for use only in Designer, so that they are hidden in the BusinessObjects end-user querying tools.


Creating classes and objectsAfter defining classes and objects, the next step is to understand how to employ these elements.


• Create a class

• Create objects

• Create classes and objects automatically

• Create classes and objects by copy and paste from another universe

• Edit object parameters

• Check integrity

• Test the objects in Web Intelligence

Creating classes

There are two ways to create a class in the Universe pane:• Manually defining a class.• Automatically by dragging a table from the Structure pane into the Universe pane.

To create a class

1. Click the existing class below which you want the new class to appear.

Note: If this is the first class you are creating, ignore this step.

Note: If you create a class when an object within a class is highlighted, you will create asubclass within that class.

2. There are three ways you can insert a class:• Click the Insert Class button from the Editing toolbar.• Select Insert ➤ Class.• Right-click in the Universe pane and choose Class from the right-click menu.

3. The Edit Properties dialog box displays.

4. In the Class Name field, enter a name.

5. In theDescription field, enter a description of the class content. Use business language thatis meaningful to the users in your description for when they review it. Avoid technicaldatabase language.


6. ClickOK.

To manually create an object

1. Click the class in which you want the new object to be placed.

2. There are three ways you can insert an object:

• Click the Insert Object button from the Editing toolbar.• Select Insert ➤ Object from the menu bar.• Right-click the class and chooseObject from the right-click menu.

The Edit Properties dialog box for the object appears.

3. In theDefinition tab.


Ensure that object names are always expressed in the end user business vocabulary. Thisname may be different from the actual column names that the object is associated with inthe database schema.

4. Type a SELECT statement in the Select box, or click the >> button to use the SQL editor.

5. Click the Properties tab and select object properties.

6. ClickOK.

Automatically creating classes and objects from a table

You can also create classes and objects simply by dragging the entire table from the Structurepane into the Universe pane in Designer. This is particularly useful if you are sure that youwant all the columns in the table to correspond to objects in the universe.

Note: The class is automatically populated with a dimension object for every column in the table.It is not advisable to do this because you are creating a universe based on the database structure,not on the requirements of the users.

You can create an object automatically by selecting a column in a table in the Structure paneand dragging it to the Universe pane. An object is created under the nearest class to the pointwhere you drop the column. The default name for the object is the column name.

You should edit the new object properties to ensure that it is appropriately named and isrelevant to end-user needs. Whenever you create an object automatically, edit the propertiesof the object to:• Change the name where appropriate.

• Enter a description.

• Change the object qualification from the default where necessary.

• Alter or remove the associated list of values settings where appropriate.

• Change other settings as required.

To automatically create an object from a column

1. Click a table column in the Structure pane.

2. Drag the column across to the Universe pane and drop the table at the desired position inthe class hierarchy. The column must be dropped under an existing class.

A new object appears in the hierarchy.

Defining a new object as a detail object

TheProperties tab in theEdit Propertiesdialog box allows you to define the object qualification.An object can be qualified as a dimension-, detail-, or measure-type object.


A detail object provides descriptive data about a dimension, and is always attached to adimension. It maps to one or more columns or functions in the database that provide detailedinformation related to a dimension.

To define an object as a detail object

1. Double-click an object.The Edit Properties dialog box for the object appears.

2. Click the Properties tab.

The Properties tab of the Edit Properties dialog box appears.

3. In theQualification zone, select theDetail button.

The Associated Dimension field appears in theQualification zone.

4. Click theAssociated Dimension field, and from the drop-down list of available dimensionobjects, select the one with which this detail object is to be associated.

5. ClickOK to confirm the change.

Working with classes and subclasses

A subclass is a class within a class. You can use subclasses to help organize groups of objectsthat are related. A subclass can itself contain other subclasses or objects.

Note: It is recommended that you do not create too many levels of subclasses (more than three).Too many levels make it difficult for users to find the objects they need.


To create a subclass

1. Right-click the class in which you want to create a subclass.The drop-down menu appears.

2. Choose Subclass.

The Edit Properties dialog box displays.

3. In the Class Name field enter the name of the subclass.

4. ClickOK.

The Universe pane should look similar to:

To delete a class or a subclass

1. There are two ways to delete a class or subclass:

• Click the class, or subclass that requires deletion. Press theDelete key.• Right-click the selected class, or subclass. Select the Clear option from the drop-down

menu.

Editing the object properties

The example below shows the properties of the dimension object, called Client Name.


As the object is currently defined, there is no SELECT statement defined to reference the Clienttable. You need to edit the definition of the SELECT statement so the Client Name object returnsthe complete client name using the appropriate columns from the Client table.

Note: The example above shows a concatenation of two columns. Depending on the RDBMS usedthe syntax can vary. Consult the documentation provided by your database vendor to see whattypes of concatenation functions are supported.


To edit the object definition

1. Double-click the object that you want to edit.

2. In theDefinition tab, type in theName field if you want to edit the object name.

3. Click the Type arrow, and from the drop-down list, select the appropriate data type for thedatabase column, or columns that the object references.

4. Click theDescription text box and type help text for the end user.This text appears in Business Objects end-user querying tools when a user selects the objectto build a query. The text describes the data returned when the user adds this object to aquery.

5. Click the Select text box and enter the SELECT statement that will be inferred when a userbuilds a query using this object.

This can be done in one of two ways:• Type the SELECT syntax in the Select field to define the columns that will be referenced.• Click the >> button to open the Edit Select Statement dialog box as displayed below.

The Edit Select Statement dialog box appears.

It is normally best to use the latter method because it enables you to specify most of theSELECT syntax from pick lists in the lower half of the screen by double-clicking the itemrequired. This minimizes typing and averts syntax errors due to typing mistakes.

6. Create the SELECT statement so the object references the appropriate table columns.


Note: You can use the fields below the text box to select the columns, operators or functionsyou need to use to enter the required SQL syntax.

7. Click the Parse button to validate the statement syntax.

8. ClickOK to close the Edit Select Statement dialog box.

The Edit Select Statement dialog box closes and theDefinition tab of the Edit Propertiesdialog box displays the SQL statement in the Select text box.

Edit Properties: Properties

The Properties tab in the Edit Properties dialog box allows users to:1. Select one of the object types in theQualification zone.

Note: By default, the object type selected will be either a dimension or measure dependenton the data type chosen on theDefinitions tab.

Dimension=Character, Date or Number

Measure=Selected by default when there is an aggregate function in the SELECT clause

Note: The Detail qualification check box will be grayed out if no dimension objects exist towhich to attach a detail object.

2. Select the appropriate options in the Associate a List of Values zone.

What is a list of values?

When you create an object, Designer automatically associates a list of values (LOV) with theobject. The LOV is not created until a user or the universe designer chooses to display a list ofvalues for the object in theQuery Panel. A SELECT Distinct query is then run against thecolumn or columns inferred by the object.

The returned data is stored in a file with an .lov extension in the universe subfolder createdunder the same folder that stores the universe file. The .lov file is then used as the source forvalues for the list. This allows the SELECT Distinct query to be run only once for an object.

When do you use a list of values?

A list of values should only be used with an object if it will provide something useful for theuser. LOVs are very useful where there is a limited set of distinct values for the databasecolumns underlying the object.

Note: If the object is likely to refer to a large number of distinct rows in the database, it isadvisable not to associate an LOV or change its configuration to avoid performance issues.

Setting LOV options

In theAssociate a List of Values zone, theDisplay button allows you to view all the values inthe database returned by this object.


To restrict the object so that some of the values are not returned when an end user uses thisobject in a query, you can click the Edit button to create a filter (or condition) in theQueryPanel that appears.

Edit Properties: Advanced

The Advanced tab allows you to set the security access level of the object and how it can beused in a query or in a report. You can select a security level which restricts use of the objectto users with the appropriate security level.

In the Security Access Level zone you can assign the following security access levels:• Public

• Controlled

• Restricted

• Confidential

• Private

If you assign Public then all users can see and use the object. If you assign Restricted, thenonly users with the user profile of Restricted or higher can see and use the object.

In the Can be used in zone, select one of the following options to define how this object canbe used in a query:• The Result check box - use this object to return results in a query.• The Condition check box - use this object to apply a condition or query filter in a query.• The Sort check box - specify the object in the ORDER BY clause of a SELECT statement.


Note: This option can increase the processing speed of a query. However, in certain editedLOV situations, it is not useful to sort at query level because block-level sorting overridesany row order of data that is stored in the microcube.

Edit Properties: Keys

TheKeys tab allows you to define index awareness for an object. Index awareness is the abilityto take advantage of the indexes on key columns in the database to speed data retrieval.

The objects that you create in Designer are based on database columns that are meaningful toan end user. For example, a Customer object retrieves the field that contains the customer name.In this situation, the customer table typically has a primary key that is not meaningful to theend user, but which is very important for database performance. When you set up indexawareness in Designer, you tell Designer which database columns are primary and foreignkeys. This can have a dramatic effect on query performance.

In the example below, primary and foreign keys have been defined on the Client Countryobject. The complete WHERE clause for the primary key is:

COUNTRY.COUNTRY_ID = CLIENT.COUNTRY_ID

If you then use Country and the Client Name object in a query, the query will not need toreference the Country table in the database; the Country data will be taken from the Clienttable directly.


Edit Properties: Source Information

For universes generated from Data Integrator, technical descriptions and formulas used tocalculate target tables from source tables are displayed in this tab.

You can specify the following types of information in the Source Information tab:

• Technical information: Technical descriptions that are available in universes generated fromData Integrator.

• Mapping information: The mapping applied within Data Integrator between the sourcetables and the target tables. The goal is not to provide the expression of the mapping, butto display it as a descriptive comment to inform the user of the source columns used in theobject definition.

• Data Lineage information: List of source columns involved in a target column. Thisinformation facilitates the impact analysis through Data Integrator and Web Intelligencereports.

It is possible to copy objects fromone universe to another. This is useful if youwant to createobjects that are similar to those already existing in another universe. You can copy thoseobjects or classes of objects and edit them as required.

Note: When you copy an object from one universe into another, be sure to validate theobject definition against the new universe structure and data source connection.


Copying and pasting objects

It is possible to copy objects from one universe to another. This is useful if you want to createobjects that are similar to those already existing in another universe. You can copy those objectsor classes of objects and edit them as required.

Note: When you copy an object from one universe into another, be sure to validate the objectdefinition against the new universe structure and data source connection.

To copy and paste objects

1. Open the universe from where you want to copy objects.

2. Select the object(s) you want to copy.

3. Click copy from the standard toolbar.

4. Open the universe to which you want to copy the objects.

5. Click paste from the standard toolbar.

Find and replace

The Find and Replace functions can be very useful when editing. You can use the Find functionto locate character strings in objects and their definitions.

You can also use the Find function in conjunction with the Replace function to edit strings.

To find a string

1. Ensure the Universe pane of the Designer window is active.

Note: If the Structure pane of the universe is active, the Find function searches for tablenames containing the specified string.

2. Click Find from the standard toolbar.

The Find/Replace dialog box opens.


3. Enter the character string for which to search.

4. Select the check box options as required.

5. Click Find Next. The appropriate object or part of the object definition will be displayedand the string will be highlighted.

6. To move to the next instance of the string, click Find Next or click the Find Next icon.

To replace as you find

1. In the Find/Replace dialog box, select the Replace tab.

2. Enter the string to search for in the Find What field and the string with which it is to besubstituted in the Replace field.

3. Select the check box as required.

4. Click Find Next.

5. Click Replace and then move to the next instance of the string by either clicking Find Nextor the standard toolbar option.

Checking object integrity

Always check the integrity of your universe after defining classes and objects.

Use the Check Integrity option to detect any errors in the SQL syntaxes used in the createdobjects.

Note: Ensure that theCheck Cardinalities box is cleared. With a large database, this will save timerunning the integrity check.

To check object integrity

1. Click the Check Integrity button.


The Integrity Check dialog box displays.

2. Select the Parse Objects check box.

3. ClickOK.

4. Designer checks the universe and displays the Integrity Check Results dialog box.

5. Identify the reason for any reported errors and resolve them.

Viewing parent tables

You can view the table in the Structure pane that is used in an object definition from theUniverse pane. This can be useful to quickly identify a table used by an object when objectnames do not easily indicate a specific table.

To view associated tables of an object

1. Right-click the object.

2. Select the View Associated Table option.

The associated tables of the object will be highlighted in the Structure pane and the listmode display (if open).

To view associated objects

1. Right-click any table.

2. Select the View Associated Objects option.

3. The associated objects of the selected table will be highlighted in the Universe pane.


Testing objects

As you create objects in the universe, test them in Business Objects end-user querying tools bybuilding and running queries. There are three things you need to test:• Do the objects exist? If not, you may have forgotten to save and export your universe since

the object you are testing was created.• Does the SQL appear correct?• Are the results of the query correct?

Remember that you must also test the joins already created in the structure.

Activity: Creating and testing classes and objects

Objective

• Create and test classes and objects.

Instructions

In this workshop you will create classes, subclasses and dimension and detail objects in theMotors universe and then test the universe’s objects and joins.1. Create the following class:

• Client

2. Create the following class and subclass:• Car• Sale Prices (subclass of Car)

3. Create a Client Name dimension object manually with the settings:• Type = Character• Description = Last name, First name• Select syntax =

CLIENT.CLIENT_LASTNAME + ', ' +CLIENT.CLIENT_FIRSTNAME

• Associate an LOV

4. Create a Client ID detail object automatically with the settings:• Type = Number• Description = Unique Client ID Number• Select syntax =

CLIENT.CLIENT_ID

• No Associated LOV

5. Check the integrity of the objects.

6. Create a Showroom class.


7. Create objects for each of the classes as identified in the tables below. Some of the propertiesfor each object have been specified for you. However, you will have to determine the datatype, qualification, and whether or not a LOV should be associated with each object.


Car class

Object DescriptionSELECT StatementObject Name

Car ManufacturerMAKER.MAKER_NAME

Maker

The style group into whicha car fits (for example,coupe, 4x4)

STYLE.STYLE_NAMECategory of Car

Model name, trim, andengine size

MODEL.MODEL_NAME +' ' + MODEL.MODEL_TRIM +' ' + MODEL.MODEL_ENGINEModel

Sale Prices class (a subclass of Car)

ObjectDescriptionSELECT StatementObject Name

Description ofprice rangebanding

SALES_PRICE_RANGE.PRICE_RANGEPrice Range

Manufacturerrecommendedretail price

MODEL.MODEL_PRICEModel Price

Showroom class


Town in whichshowroom exists

SHOWROOM.SHOWROOM_TOWNShowroom Town

Name of showroomSHOWROOM.SHOWROOM_NAMEShowroom

Address of showroomSHOWROOM.SHOWROOM_ADDRESSShowroom Address

Client class


Country in which clientresides

COUNTRY.COUNTRY_NAMECountry

Region of country in whichclient resides

REGION.REGION_NAMERegion

Area of Region in whichclient resides (for example,county or state)

CLIENT.CLIENT_AREAArea



Client Town Town or city in which clientresides

CLIENT.CLIENT_TOWN

Address of clientCLIENT.CLIENT_ADDRESSClient Address

Postal or Zip CodeCLIENT.CLIENT_AREA_CODEArea Code

Phone number of clientCLIENT.CLIENT_PHONE_NOPhone Number

Unique Client ID NumberCLIENT.CLIENT_ID Client ID

8. Modify the properties of the following objects so that they are qualified as detail objects,and associated with the Client Name dimension object:• Client Address• Area Code• Phone Number

9. Modify the properties of the Showroom Address object so that it is qualified as a detailobject, and associated with the Showroom dimension object.

10.Create a class called Sales and two subclasses in the Sales class:• Sales Details• Sales Dates

Sales Details class (a subclass of Sales)


Unique Invoice ID NumberSALE.SALE_IDInvoice ID Number

Sales Dates class (a subclass of Sales)


Date of saleSALE.SALE_DATESale Date

11.Drag the FINANCE_PERIOD table from the Structure pane and drop it in the Universepane.

Note: Delete the FP_Start and FP_End objects that are automatically created.

12.Edit the objects that have been created automatically in the new Finance class, according tothe table below.


Financial Period class


For example, FY03-04FINANCE_PERIOD.FP_YEARFinancial Year

For example, Q1FINANCE_PERIOD.FP_QUARTERFinancial Quarter

For example,Month 01FINANCE_PERIOD.FP_MONTHFinancial Month

13.Make sure you have defined each object using the appropriate object type.

The Universe pane in Designer appears like this:

14.Save the universe.

15.Check the integrity of the objects, and make any alterations required.

Note: Test the validity of the joins also.

16.Save the universe again and export to the BusinessObjects repository.

17.Test the universe by building queries by using the new objects:• Log onto Web Intelligence with the User name administrator.


• SelectNew ➤ Web Intelligence Document.• Select Motors universe. The Web Intelligence Java report panel for the Motors universe

opens.• Build a new query in the Report Panel using the objects you have created.• Click Run Query to view the final results displayed in the report.


Quiz: Creating dimension objects1. Which of the three types of objects contain aggregate functions that map to statistics in the

database?

2. When you are testing objects, what are the three things for which you need to test?

3. If each object maps to a column or function in a target database, when used in a query, whatkind of statement does the object infer?



• Describe classes and objects• Create classes and objects


Lesson 5Creating Measure Objects

Lesson introductionThis lesson describes how to create measure objects and test that they produce the correctresults when used in queries.


• Explain measure object concepts• Create measure objects

119Creating Measure Objects—Learner’s Guide

Measure object conceptsAfter completing this unit, you will be able to:

• Define measure objects• Determine levels of aggregation

Defining measure objects

Ameasure object returns numeric information. Measure objects are very flexible because theyare semantically dynamic. Thismeans that the values they return in a querywill vary dependingon the dimension and detail objects that are used with them.

You can see from the illustration that two separate queries, using the same Sales Revenuemeasure object, but different dimension objects, results in the measure returning differentvalues.

You create a measure object by using an aggregate function in the SELECT definition of theobject. The five basic aggregate functions are:• Sum• Count• Average• Maximum• Minimum

Ameasure object returns numeric data from the database that aggregates up or down accordingto the dimension objects in the query. The most regularly used aggregates are listed above.However, there are others that can be used. The full set of aggregate functions is held in theNumber Functions pick list of the Edit Select Statement dialog box.

How a measure infers SQL

When a query uses a measure object with a dimension or detail object, the query definitionautomatically infers a GROUP BY clause in the SELECT statement.


Inference of the GROUP BY clause is dependent on the SQL rule: When the SELECT clause linecontains an aggregate, everything outside of that aggregate in the clause must also appear inthe GROUP BY clause.

That iswhy dimension and detail objectsmust not contain aggregates. Any dimension or detailthat is used in the same query as a measure object will always be included in an inferred GROUP

BY clause.

When a query includes only a measure, the SQL inferred is the same as when the query usesa dimension object:• The SELECT clause shows the object selected in the query with the syntax including the

aggregate function.

• The FROM clause shows the tables involved in the measure object syntax.

• The WHERE clause identifies the joins among the tables involved.

The query result shows one row of the total revenue value.

In this example, the query includes only the Sales Revenue measure so the inference enginedoes not include a GROUP BY clause in the SQL statement.

When a query uses at least one dimension or detail object and a measure, the inference engineincludes a GROUP BY clause with all the objects except the measure in the SQL Statement:• The SELECT clause shows the object(s) and measure selected in the query with the syntax

including the aggregate function.

• The GROUP BY clause includes all the objects except the aggregate.

In this example, the query includes the Sales Revenue measure and the Country object so theinferred SQL statement includes a GROUP BY clause with the Country.


In this example, the query includes two dimensions (Country and Region) so the inferenceengine includes both dimensions in the GROUP BY clause. As a result, the values returned forthe Sales Revenue measure object are aggregated to a lower level, the Region. This mechanismin the inference engine allows the measure objects to adapt dynamically to other, associatedobjects.

The Query Process

How do the Business Objects end-user querying tools process the measure object in a query,and how do the values get projected?

There are two levels of aggregation in the query process:• Aggregation at SELECT level

• Aggregation at projection level


Aggregation at SELECT level

Aggregation at SELECT level occurs first in the query process:• The user creates a query.

• Web Intelligence defines the SQL from the query and sends a SELECT statement to the targetdatabase.

• The data is returned to the microcube. The first level of aggregation now takes place in themicrocube.

• The results are projected in the query. The microcube projects the aggregated data onto thereport, the SQL statement is inferred against the database, and the results are returned tothe microcube.

Aggregation at projection level

When you run a query, the resultset of the SELECT statement is stored in the microcube. Alldata then held in the microcube is projected into a block (the table or chart in the report).Therefore, because data is projected from the lowest level held in the microcube, no projectionaggregation takes place.


However, when you edit the table, for example, by removing a column, and therefore projectonly partial data from the microcube, aggregation is required to show measure values at ahigher level. The data in the microcube remains unchanged.

For instance, if you do not project the region data into the block, the four rows related to USAneed to be reduced to one to show the overall Sales Revenue for that country. In this instance,a sum aggregation is required.

When projecting all variables in the microcube, no aggregation takes place.

When projecting only some variables from the microcube, aggregation occurs.

Projection aggregation is separate from SELECT aggregation and depends on how you definethe measure object properties when you create the measure object using Designer.

Setting selection and projection aggregates

Statistically, only certain SELECT and projection aggregates are compatible.

Recommended Projection AggregateSELECT Aggregate

• Sum• Sum

• Sum• Count

• None• Average

• Maximum• Maximum

• Minimum• Minimum

For the reports to present statistically correct results for a measure object both at query andprojection level, the SELECT and projection aggregates need to complement each other.

However, as a universe designer, if you configure a measure differently, the Business Objectsend-user querying tools will not stop you.

Note: With the exception of Average, the correct projected aggregate is selected by default. Whenyou set the SELECT syntax to Average, for example Avg(SALES.SALES_TOTAL), the projectionaggregation for this object would automatically be placed as a SUM. This would need to be changedmanually to NONE.


Creating measure objectsAfter completing this unit, you will be able to:

• Create measure objects• Test measure objects in Web Intelligence

Measure objects

You create measure objects in the same way that you create a dimension or detail object. Theycan be created using the automatic or manual method.

It is recommended that you groupmeasure objects together in separate classes fromdimensionand detail objects, if they are generic. In other words, if they can be used in the same query asany dimension and detail object in the universe, then they are considered generic, and youmust group them in separate classes.

If they are only compatible with certain objects, however, then you may want to place them inthe same class as those objects, to indicate this fact to the report designers.

It is important to remember the following when you create measure objects:

In the Definition tab

• TheData Type field must be set toNumber.

• The Select field must include an aggregate function.

Tip: It is best to use the Select Edit dialog box to insert the SELECT clause content of a measureas you can then use the Function and Columns pick lists.

Note: When an aggregate function is used in the Select Edit dialog box, the qualification isautomatically set toMeasure type.

In the Properties tab

• The qualification must be set as aMeasure type.

• In the Function field, make sure the function you use is compatible with the aggregate usedin the SELECT statement.

• Ameasure object should not have a list of values associatedwith it. Therefore, theAssociatea List of Values check box should be unchecked.


Testing measure objects

When you test ameasure, youmust be far more rigorous in your checks thanwith a dimensionor detail object. This is because you have to check that the values of the measure aggregatecorrectly both at SELECT and projection level.

The three elements to testing a dimension or a detail object are:1. Check that the objects exist.

2. Check the inferred SQL.

3. Check the query results.

For measure objects, the additional elements are:• Repeat with the other dimensions.

• Make a query with a minimum of two dimensions and a measure.

• To validate the accuracy of the measure aggregate, it is recommended that you test it withat least three separate queries.

Testing measures at SELECT level

To test the inferred SELECT statements for ameasure object, youmustmake at least two separatequeries using different dimension objects to produce different levels of aggregation. Three ormore queries are preferable.

In each instance, you must check the following:• The inferred SQL of the query

In particular, you should check the GROUP BY clause has been inferred correctly.


Note: If it has not been inferred at all, it is likely that you have set a calculation and not anaggregate in the Select field of the measure object properties.

• The results of the query

Check that the query produces the correct results.

Testing measures at projection level

To test for projected aggregation, you need to build a query containing at least two dimensionobjects, as well as the measure object you are testing. This allows you to project from otherthan the lowest level of data held in the microcube and therefore test aggregation.

Activity: Creating and testing measure objects

Objective

• Create and test measure objects.

Instructions

1. Create the following subclass in the Sales class:• Sales Figures

2. Create a Sales Revenuemeasure object with the settings:• Type = Number• Description = Total Sale Invoice Revenue• Select statement =

SUM(SALE_MODEL.SALE_QTY * MODEL.MODEL_PRICE * ((100 - SALE.SALE_SALE_DISCOUNT) / 100))

• Function = SUM• No associated LOV


3. Save and export the universe.This allows you to test the Sales Revenue object in Web Intelligence.

4. Log onto Web Intelligence.You will test the Sales Revenue object by running three queries.

5. Create a new query based on the universe you just exported, containing the Sales Revenueobject.Note the value returned.

6. Test the Sales Revenuemeasure object by creating a second query, using the following steps:a. Edit the query created in the previous step, and click Add Query.b. Select theMotors.unv.c. Create a new query with Country and Sales Revenue.

Check the SQL and note the GROUP BY clause. It should contain the SQL for the Countryobject.

d. Click Run Queries.

Note: You will be prompted to select a way to display the new query. You can leave thedefault option to add a new tab to the report or you can select the option to display thetable in the current report.

e. Apply a SUM calculation to the Sales Revenue column in the new projected block. Doesthe sum match the value shown in the first table? Note the value of the Sales Revenuein a row of the block (for example, USA).

7. Test the Sales Revenue measure object by creating a third query, using the following steps:a. Edit the second query and then click Add Query.b. Create a new query with Country, Region, and Sales Revenue.c. Check the SQL and note the GROUP BY clause. It should now contain the SQL for the

Country and Region objects. Click Run Queries.d. Apply a break to theCountry column and apply the sum calculation to theSales Revenue

column of the new projected block. Does the Country group summatch the value of thenoted block row in the second table (for example, USA)?

e. Edit the query. Change the projection to the block from the microcube by removing theRegion column from the block. Does it aggregate to Country level correctly?

f. Edit the query again. Change the projection to the block from themicrocube by removingthe Country column from the block. Does it aggregate to the total Sales Revenue levelcorrectly?

g. Edit the query again. Add the Showroom andMaker objects.h. Using drag and drop, insert two new tables, one to showShowroom andSales Revenue,

and the other to showMaker and Sales Revenue, and apply a sum to both tables. Notethe total values remain the same. The final version of the report should look similar tothis:


8. In Designer, create the following measure objects in the Sales Figures subclass and testthem.The SQL code for the SELECT properties of each object has been specified for you. However,you will have to determine the appropriate projection function aggregate.

Object DescriptionSelect StatementObject Name

Total Cost of Car SalesSUM(SALE_MODEL.SALE_QTY * MODEL.MODEL_COST)Cost of Car Sales

Total Number of CarsSold

SUM(SALE_MODEL.SALE_QTY)Number of Cars Sold

9. Create the measure objects listed below.• In the Car class and Sale Prices subclass: Lowest Priced Value based on Manufacturers

recommended retail price.• In the Car class and Sale Prices subclass : Highest Priced Value based on Manufacturers

recommended retail price.• In the Client class: Number of Clients.

10.Save and export the universe.

11.Test the new objects in Web Intelligence.


Quiz: Creating measure objects1. Measure objects are very flexible because they are semantically dynamic. What does this

mean?

2. Measure objects are created in the same way as a dimension or detail object. However, theobject properties differ in two ways. What are they?



• Explain measure object concepts• Create measure objects



Lesson 6Using Lists of Values

Lesson introductionThis lesson explains how you can add, modify, or remove a list of values (LOV) for an object.It also introduces how to create a cascading list of values in Designer and how to use them inWeb Intelligence.


• Create a list of values• Work with LOVs in Designer• Create a cascading LOV

133Using Lists of Values—Learner’s Guide

Creating a list of valuesA list of values is a list that contains the distinct data values associated with an object.


• Explain what a list of values (LOV) is• Use a list of values in Web Intelligence

What is a list of values?

When you create a dimension or detail object in Designer, it is automatically assigned anassociated list of values, or LOV. This list does not physically exist when you create an object,but by default the object has the ability to query the database to return a list of its values whenused to build a query.

Lists of values are based on the results of a SELECT Distinct query on the column or columnsheld in the Select statement in the object’s Edit Properties dialog box. If you select the Exportwith Universe option in the Associate a List of Values pane of the Properties tab, the list ofvalues is converted to XMLwhen you export the universe, and then stored in a .unw file in theCentral Management Server (CMS).

The first time a list of values is used to filter results returned by a query, the LOV is stored inan encrypted file on the local file server in the sessions folder.

As you create objects in the universe, use the following questions as a guide to help you decidewhether to associate an LOV to an object or not:• Do the users need to see a list of values for this object? Are they likely to want to apply

query filters or conditions on this object?

• Is the data dynamic or static? Will the data be updated frequently?

• How long will it take to run the SELECT Distinct query?

• What does the list need to include?

Using a list of values (LOV)

When users build queries, they can define query filters to restrict the amount of data returnedby a specific object used in the query. To do this, they view the list of values for that object inorder to specify which value(s) will be returned. The LOV for the object appears in the Filteror Editor, which helps the user choose the terms for the filter.

For example, a manufacturer object with the SELECT clause for the manufacturer name columnwill have an LOV that contains all the available distinct car manufacturer’s names. A user whowants to limit the query to a single manufacturer could select that name for the query filter bychoosing it from the LOV.


Working with LOVs in DesignerA list of values is a list that contains the distinct data values associated with an object.


• Associate an LOV with an object• View the contents of an LOV• Set options for generating an LOV• Modify the contents of an LOV• Create a hierarchical view of an LOV

Associating an LOV with an object

By default, an LOV is attached to every dimension and detail object that is created in Designer.When you create a dimension or detail object in Designer, it is automatically assigned anassociated list of values, or LOV. This list does not physically exist when you create an object,but by default the object has the ability to query the database to return a list of its values whenused to build a query.

There are three things to keep in mind, as a universe designer, when deciding whether or notto associate an LOV to an object:• An LOV is based on a SELECT Distinct query that is fired at the target database; this could

have potential performance implications for the efficiency of Business Objects end-userquerying tools.

• The only purpose for creating an LOV is to assist the end user in choosing an operand valuefor a query filter.

• The LOV only holds values that exist within the database.

It is therefore recommended that you do not provide an LOV for the following types of objects:• All measure objects.• Any object where the LOV consists of a large number of values.• Any object where the list on its own would be meaningless.

To view an object’s default LOV properties

1. Double-click the object to open the Edit Properties dialog box for the object.



3. If you want to turn off the LOV for this object, click the Associate a List of Values checkbox to clear it.

To view the contents of an LOV in Designer

1. Double-click the relevant object to open the Edit Properties dialog box.


3. In the Associate a List of Values zone, click theDisplay button.

A SELECT Distinct query is fired at the target database and the LOV displays.

4. Click the Cancel button to close the window.

To create a file to hold the contents of the LOV query in Designer, use the same procedure, butinstead of clicking Cancel at step 4, clickOK. In that case, the list is saved as an .LOV file inthe universe subfolder on the file system.

The default location is the Universe subfolder of the default installation folder:C:\Documents and Settings\<user_name>\Application Data\Business Objects\Business Objects 11.5\Universes\@<server_name>\<universe_name>

The name of the LOV file is the same name as shown in the List Name field, in the Propertiestab.

As a designer, you can edit the list name to call the file anything you want (over 100 characterslong), provided that the file ends in an .LOV extension. Clicking the Restore Default buttonchanges the name back to the default file name.


Setting options for generating LOVs

By default, the first time that an LOV is used in a user login session, the system fires a queryat the target database and uses the results to populate the list. Thereafter, the .LOV file fromthis query is referred to each time the LOV is used.

However, you can alter the strategy for refreshing the list by selecting options from theAssociatea List of Values zone, in the Edit Properties dialog box.

Note: The next section describes the following List of Values options:

• Automatic refresh before use option

• Export with universe option

Automatic refresh before use

If you select this check box, the system sends the SELECT Distinct query to the target databaseevery time the user selects the LOV. This refreshes the contents of the list muchmore frequentlythan the default strategy, where the list is refreshed only the first time it is used in a user loginsession.

It is recommended that you select the Automatic refresh before use check box if the contentsof the list are dynamic and frequently changing. If the contents of the list are stable andunchanging, you can increase speed and efficiency by clearing this check box.

Export with universe

If you select the Export with universe check box, the list of values is converted to XML whenthe universe is exported, and stored in a .unw file. This file is stored in the BusinessObjectsCentral Management Server (CMS).

Modifying the contents of the LOV

In Designer, you can modify the contents of the list in two ways:• Remove values from the list by creating a filter.

• Add data to the list by adding columns to the list.

The remaining two options, Allow users to edit this list of values andHierarchical Display,are not available for users creating reports with Web Intelligence.


To apply a condition to an LOV

1. In Designer, in the object’s Edit Properties tab (in theAssociate a List of Values zone), clickEdit to the left of the Display button.

The DesignerQuery Panel displays, showing the default query for the LOV. The activeobject is listed in the Result Objects.

2. Drag an object that youwant to serve as a condition on the list of values for the active objectover to the Conditions pane.

3. Double-click an operator in theOperators pane.

4. Double-click an operand in theOperand pane.

5. Select or type values as required.

6. Click Run to save the condition and close the DesignerQuery Panel.

7. ClickDisplay to view the restricted list of values.If a blank list appears, click Refresh. The values appear in the list.

8. ClickOK to accept the modified list.

The .LOV file in the universe subfolder updates with the modified list. This is the LOV thatthe end users see when they use the edited object in a query.

Editing the LOVs for the entire universe

If you want to view all the objects in the universe that have LOVs associated with them, andpossibly edit some of these LOVs at the same time, you can edit the lists from the DesignerTools menu.

To edit the LOVs from the Tools menu

1. From the Toolsmenu in Designer, select List of Values.

2. Select Edit a List of Values from the drop-down menu.

The List of Values dialog appears displaying all the objects in this universe that have anLOV associated with them. From here, you can select any of these objects to display, edit,purge and refresh their LOV.


3. Click the +box next to each class name displayed to see the objects in this universe that havean LOV associated with them.

4. Select an object from the list.

5. ClickDisplay.

The list of values for the selected object displays.

6. ClickOK to close the List of Values dialog box.

The Tools ➤ List of Values ➤ Edit List of Values option is useful if you want to edit allthe LOVs in the universe at the same time, instead of displaying the Edit Properties dialogbox for each object separately.

Adding data to the list by adding columns

The second way you can modify the LOV is to add more data to the list by adding columns toit. This helps end users to find the value theywant. It is also an appropriatemethod for an LOVthat contains a lot of values.

To add additional columns to an LOV

1. Double-click on an object to open the Edit Properties tab.

2. Click on the Properties tab.

3. Select Edit (in the Associate a List of Values zone).

The DesignerQuery Panel displays.


4. Drag the objects youwant to place in the hierarchy into theResult Objects pane to the rightof the existing object and place the respective sorts on them.

5. Click Run to save the LOV query and close the DesignerQuery Panel.

6. In the Properties tab of the object’s Edit Properties dialog box (in the Associate a List ofValues zone), click theDisplay button to see the LOV.

Note: If the list is blank, click the Refresh button to update the list.


Creating a cascading LOVA cascading LOV is a feature in Designer that allows you to associate an LOV to a series ofobjects defined in a hierarchy.When a user applies a prompted query filter to one of the objectsused in the cascading LOV, Web Intelligence prompts the user to select a value for each levelof the hierarchy.

This feature only applies to Web Intelligence XI R2.

Note: You remove a cascading LOV in the same way that you remove an ordinary LOV, byediting the object properties and deleting the condition in the object definition.


• Set up a cascading LOV• Use the cascading LOV in Web Intelligence

Setting up a cascading LOV

A cascading LOV is a sequence of lists of values associated with a hierarchy of objects in auniverse. As universe designer, you define prompts for each hierarchy level andwhen the useradds one of the objects to a query, the query prompts the user to select a value for each level.

Universe designers build the prompt(s) in the object definition, and report designers and powerusers use it when they create and refresh reports using queries.

A universe designer defines the universe so that the user is always required to answer a seriesof prompts to specify the values in a hierarchy of dimensions to be displayed in the report.Only the data concerning the selected values is returned to the microcube.

To build a cascading LOV on an object

1. From the Toolsmenu in Designer, select List of Values.

2. Select Create cascading Lists of Values from the drop-down menu.

The Create Cascading List of Values dialog box appears.

3. Open the appropriate class and double-click the object to move it into the Cascading Listof Values list.By default, text appears in the Prompt Text zone to set the text that users will see if thisobject is used in a prompted query filter after you add the next object.

4. Double-click additional objects that need to appear in hierarchical order in the cascadinglist of values.Edit the prompt text if required.

5. Verify that theHierarchical View check box is selected.

6. ClickGenerate LOVs to create the list of values.


If LOVs already exist for the selected objects, you will be prompted with a message askingwhether you want to overwrite the existing values.

7. ClickOK.The Create Cascading List of Values dialog box closes.

8. Save and export the universe.

To test the cascading LOV in Web Intelligence

Now that you have assigned LOVs to objects that are grouped together in a hierarchy as acascading LOV, you can create a query that builds one of the objects into a prompted queryfilter.1. InWeb Intelligence, build a query and create a prompt on one of the objects in the cascading

LOV.

2. Click Run Query.The Prompts dialog box appears. The Prompts dialog box displays the list of values for allthe objects you placed in the cascading LOV in Designer, in reverse order.

Note: If you are sure you know the exact value that interests you, you can always type inthe Type a value text box.

3. Scroll down the list of values and click the + box to expand that folder.

4. Expand the further + boxes to select the lowest level value for your query.The little arrow displayed next to the prompt text at the top of the Prompts dialog boxchanges to a green check mark and the value you have chosen appears in the prompt.

5. Click Run Query to create the report.The report displays the selected values.

Activity: Using a cascading LOV in Web Intelligence

Objective

• Associate a cascading LOV to an object.

Instructions

1. In Designer, create a cascading LOV using the objects in the Car class.


3. Build a query in Web Intelligence that shows the number of cars sold per showroom andprompts the users to select the Category of Car that they want to see in the report.

Note: At the end of this activity, please remove the cascading list of values using thefollowing steps:• In Designer, change the object definition to associate a standard list of values for all

objects in the Car class.


• Save and export the universe.


Quiz: Using lists of values1. By default what values are contained in a list of values (LOV)?

2. What are three things that a universe designer should keep inmindwhen decidingwhetherto associate an LOV with an object?

3. For what types of objects is it recommended not to provide an LOV?



• Create a list of values• Work with LOVs in Designer• Create a cascading LOV



Lesson 7Resolving Loops in a Universe

Lesson introductionThis lesson describes loops, a particular type of join issue that can arise as you create joinsbetween tables in your schema. It explains how you can detect and resolve loops to ensure thatthe join paths taken by queries run on the universe return correct results.


• Understand loops• Resolve loops using shortcut joins• Resolve loops using aliases• Resolve loops using contexts

147Resolving Loops in a Universe—Learner’s Guide

Understanding loopsA loop is a join path issue that arises from theway that tables are related in a relational database.Loops can produce instances where a query returns too few rows of data.


• Understand the causes of loops• Detect loops in a universe structure

Recognizing loops

A loop exists when the joins between tables form a closed path.

For example, in the table layout above, the designer has added joins between the tablesShowroom and Country to create two linked sets of information.• One set links the car sale details, the client, the client’s region and the client’s country of

residence.

• The other set links the car sale details, the showroom, and the country where the showroomis located.

Together, these joins form a loop.

Problems caused by loops

Suppose users of theMotors universe want to produce reports showing the revenue generatedby car sales to clients, including both the location of the showroomwhere the cars are sold andthe address (including country) of the clients.

The designer adds the tables needed to provide this information and creates the joins as shownin the previous example. The designer has also created objects for the Showroom Country,Client Country, and Sales Revenue.


If the loop was allowed to remain and a query could be run using the Showroom Country,Client Country and Sales Revenue objects, the report results will be incorrect. The report wouldsuggest that only clients from the US bought cars in the US showrooms, and only clients fromthe UK bought cars in the UK showrooms. However, the report would not show any clientsfrom any other countries.When you know that there are clients from other countries, this resultindicates that there is a problem with the report.

Loops in a universe schema and not in the database

In a database, multiple paths between tables can be valid and implemented to meet specificuser requirements. When each path is included individually in a query, it returns a distinct setof results.

However, a schema that you design in Designer often needs to allow queries that includemorethan one path, which a relational database may not be designed to handle. As a result, theinformation returned can be incorrect.

The rows that are returned are an intersection of the results for the path, so fewer rows arereturned than expected. It is often difficult to determine the problem when you examine theresults.

What is the loop doing?

The joins in the Structure pane are used to create the WHERE clause in the inferred SQL of aquery. Joins restrict the data that is returned by the query. In a loop, the joins will apply morerestrictions than the designer intended, and the data returned will be incorrect.

This is an example of a WHERE clause created by a loop:WHERE{COUNTRY.COUNTRY_ID=SHOWROOM.COUNTRY_ID}AND {COUNTRY.COUNTRY_ID=REGION.COUNTRY_ID }AND {REGION.REGION_ID=CLIENT.REGION_ID }AND {CLIENT.CLIENT_ID=SALE.CLIENT_ID }AND {SHOWROOM.SHOWROOM_ID=SALE.SHOWROOM_ID }AND {SALE.SALE_ID=SALE_MODEL.SALE_ID }AND {SALE.SALE_TYPE= 'S' }

Notice that the two joins at the top of the SQL statement are both applying a restriction to theCountry table, which is serving two purposes:• It is being used as the Lookup for the Showroom Country

• It is also the Lookup for the Client Country

This creates a restriction so that data is returned onlywhen the ShowroomCountry is the sameas the Client Country. Consequently, the report shows only the revenue generated byUS clientsin the US showrooms and by UK clients in the UK showrooms. In summary, while the aboveloop does infer legitimate SQL, the results will not include all intended values. Therefore, aquery on a universe involving such a loop will return misleading data. To avoid this, the loopmust be resolved.


Resolving loops

Loops are an inherent problem when writing SQL statements. There are various techniqueswithin SQL that you can apply to resolve loops.

How Designer deals with loops

There are automaticmethods built into Designer that can be used to identify and resolve almostall loop problems. The two main methods of resolving loops are:• Aliases

• Contexts

Loops can be resolved by creating aliases and contexts manually. However, depending on thecomplexity of a universe, this can be a cumbersome task. There is functionality built intoDesigner that allows for automatic detection and resolution of loops. This functionality canonly be reliable if cardinality has been defined correctly for each join in the universe.Furthermore, due to performance implications, it is recommended that all cardinality be setmanually at the time each join is created.


Resolving loops using aliasesOne way to solve a loop in the universe structure is to create an alias table.


• Describe aliases• Resolve loops using aliases• Resolve self-join loops using aliases

About aliases

An alias breaks a loop by using the same table twice in the same query for a different purpose.The alias is identical to the base table but with a different name. The data in the alias is exactlythe same as the original table, but the different name tricks SQL into using the same databasetable for two different purposes.

The Country table has already been identified as a shared lookup table because it is servingtwo purposes in the query you are trying to run (providing data for the Client Country andalso for the Showroom Country). In the example above, you can see the Country table joinedto the Region table for the Client side of the query. The Country table also is the Showroomtable for the Showroom side of the query.

Note: Another way of spotting the problem table in a loop is that it will have only the one end ofthe one-to-many joins going into it. Check the other tables in the loop. If you find no others withonly one end joins, the loop can be resolved using an alias, assuming there are no other tables joinedto country.

To resolve the loop, you need to use the same table (the Country table) twice in the same querywhen it is being used for different purposes. However, you cannot do this in SQL unless youcreate an Alias table.

You can resolve the loop satisfactorily by creating only one alias table in the example we havebeen using. The Region join uses the original Country table, while the Showroom join uses thealias table. However, you could create a separate alias table for each join in the original table.In the past, thiswas necessary for some relational databases. Today, it is not necessary.However,some universe designers prefer to alias both tables.

Detecting loops and inserting aliases

The Designer module has automatic tools that detect loops and create aliases for you.

You can use theDetect Loops orDetect Aliases toolbar icons, to automatically detect andindicate the tables causing loops in the active universe. Detect Aliases proposes candidate tablesthat you can edit, and insert in the schema.

Note: Before using Detect Aliases, verify that all the tables in schema are linked by joins, andthat all cardinalities are set.


To detect loops using the automatic detection tool

1. Click theDetect Loop button.

The system highlights the loop in the Structure pane, and displays the Loop Detectiondialog box.

2. The Loop 1/1 indicates how many loops have been detected. If there are others, you canuse the forward and back arrowbuttons to check each loop. Themessage beneath the buttonsindicates (in this case) that the loop can be resolved with an alias.

3. Click Insert Alias in the Loop Detection dialog box.

Designer automatically creates an alias for the required table. You may need to move thenew alias table so that you can see the Structure pane.

Note: The original table name will show up in brackets in the Alias table header.

4. Close the Loop Detection dialog box.

The Structure pane will look similar to this:


In the example diagram, the Country_Showroom alias table has been created in the Structurepane, the join between this Alias table and the Showroom table has been made automatically,and the loop has been broken.

Note: When the problem table has two purposes, Designer might nominate either of the two as thecandidate for the Alias table.

To insert an alias automatically

Designer has an automatic tool that detects the tables that could be aliased to resolve loops.1. Click theDetect Aliases button.

The system displays an Alias Detection message similar to the following:

If you have not yet set cardinalities, this message reminds you that you must do so first. Ifcardinalities have already been set, the reason for the message may be a self-restricting joinwithin the universe structure. Cardinality is not relevant for these types of joins and sodesigners tend not to set cardinality for them. However, to avoid the message, you couldmake self-restricting joins one-to-one.

2. ClickOK.

The Candidate Alias dialog box displays.

3. Select a table name and click Rename.The Rename Table dialog box displays.

4. Enter the new name for the alias and clickOK.

The Rename Table dialog box closes and the new alias name is shown in the right panel.

5. To create the alias table, click Create.

Designer displays a confirmation request.

6. ClickOK to create the alias table.

Note: If there are several candidates for aliases, you can then repeat the process for the nexttable. When there is only one candidate, the Candidate Alias dialog box closes.

Tip: Be careful not to delete the original table. Once you have created one or more aliastables, it’s a good idea to click beside the original table in theStructurepane and typeAliasedtable Do not remove, for example, to remind you not to delete it.


To insert an alias manually

Instead of using the Loop Detection or Alias Detection tools, you can create the alias manually.1. Select the table for which you want an alias by clicking the table header.

2. Insert an alias using one of the following methods:• Click the Insert Alias button.• Right-click the table and select Alias from the right-click menu.

3. Enter the new name for the alias table and clickOK.

This creates an alias table for the selected table.

Note: The original table name appears in brackets in the Alias table header.

4. Remove the appropriate join from the original table.

5. Reset the join to the alias table.

6. Set the cardinality for the join.

The Structure pane should now look the same as when using the first method, the LoopDetection tool.

Redefining objects

When you create an alias table, check that any existing objects that are defined from the originaltable still refer to the right table. They may need to be defined from the alias table to infer thecorrect SQL and get the correct result.

Finding objects defined from a table

In a simple universe, it is not difficult to find the objects that have been defined from a table.There is a utility in Designer that allows you to easily determine all existing objects that pointto a single table in the structure of the universe.

Designer provides an option to assist in finding the relevant objects.1. Right-click the header of the original table in the Structure pane.

2. Choose View associated objects from the right-click menu. This highlights all the objectsthat were defined from the original table in the Universe pane. Redefine the highlightedobjects to make sure they point to the correct table.

3. Double-click the affected object to open theObject Properties dialog box.

4. Redefine the SELECT statement to use the alias table instead of the original table.

5. ClickOK and then save the universe.


Listing and renaming aliases

You can list aliases and rename them. To invoke the aliases list:1. Select the List of Aliases option from the Tools drop-down list.

The List of Aliases panel appears.

To rename an alias from the List of Aliases panel

To rename aliases from the list of aliases:1. Click the alias you want to rename.

2. Edit the alias name in theNew Name field and clickOK.

Note: The alias name changes in the universe structure, any object referencing the alias,and context lists.

Choosing which alias method to use

DisadvantagesAdvantagesMethod

may show other loops to beresolved by contexts

can view loops beforeapplying them

Detect loops

no visual check prior toacceptance

finds all candidate aliasesexclusively

Detect aliases

must understand how toidentify the need for candidateanalysis

choose table to alias,minimizing object redefinition

Insert alias

Whichever method you choose, youmust always redefine objects that now use the Alias table.

Resolving self-join loops using aliases

A self-join is a join from one column of a table to another column of the same table.

A classic example of when such a join is required is in a situation whereby you want to reporton the hierarchical structure of an organization via a Personnel database. In such a situation,it is most probable that all employee records are held in a single table, irrespective of status.Hence, a self-join is required to report on the hierarchical relationship between those employees.


For example, in theMotors database there is an employees table that contains columns as shownbelow:

Each employee is uniquely identified by the Emp_Id field, and each employee has a manager,who is identified by the Emp_Mgr_Id field.However, themanagers are themselves employees,and the table therefore contains a hierarchical structure.

If youwant to add a join to link each employeewith their respectivemanager, the obviouswayis to link the Emp_Mgr_Id field to the Emp_Id field, as in this example:

The code used to identify the manager (Emp_Mgr_Id ) is itself an employee code. You cantherefore use it to look up the Emp_Id codes in the Employee table and identify the manager’sname.

This is effectively a loop, as the path forms a closed circuit. However, we cannot resolve it byusing the usualmethod of detecting the cardinalities and then detecting aliases. This is becausethe cardinality detection tool cannot work on a self-join. Moreover, a structure expressed thisway will not infer the correct SQL.

To resolve a self-join with an alias

1. Right-click the table header and choose Alias from the right-click menu.

2. Enter an appropriate alias table name.

3. ClickOK.

4. Draw the join between the original table and its alias.


5. Double-click the join.The Edit Join dialog box opens.

6. Set the cardinality for the join.

7. When the self-join has been resolved, you can create separate objects for both tables.


Resolving loops using shortcut joinsAnother way to solve a loop in the universe structure is to use a shortcut join.


• Describe how shortcut joins can make a query more efficient• Resolve loops using shortcut joins

Using a shortcut join

A shortcut join is a join that links two tables together but bypasses intervening tables that existin the universe. This is used when designing universes where it is possible in certaincircumstances to make the inferred SQL more efficient.

For example, in the Motors universe, the geographical information relating to clients comesfrom the Client, Region, and Country tables:

If an end user runs a query including Country and Client (but not Region) objects, you willfind that the inferred SQL includes the joins to the Region table. This is necessary because theRegion table forms the link between the Client and Country tables. However, the additionallookup decreases the efficiency of the SQL.

You can overcome this inefficiency bymaking a join directly from theClient table to the Countrytable. Now if a user builds a query just using Country and Client, the query will not have torefer to the Region table.

You now have a loop. In this case, you do not have a multipurpose lookup table scenario, andshould therefore not alias.

Instead you would convert the created join to a shortcut join to break the loop.


To convert a standard join to a shortcut join

1. Double-click the join that you want to convert to a shortcut join.


2. Click the Shortcut join check box just below the Cardinality zone.

3. ClickOK to close the dialog box.

The join has been redefined as a shortcut join, which appears in the Structure pane.

If you were to try detecting loops, none would be detected. The shortcut join, in the aboveexample, is telling the SQL only to use this join if the Region table is not included in thequery. Therefore, there is no loop, and the efficiency of the SQL has been improved.

Shortcut joins are not automatically detected for contexts. If you want to include them in acontext you have to manually edit the context. However, this is not always desirable.

Ideally, shortcut joins should bypass contexts when specific queries do not require one ormore contexts to return the results, and therefore should be left as standalone or isolatedjoins. The efficiency gains of a shortcut join are based on the fact that it spans across contexts.

In the Motors universe, a shortcut join can be the ideal way of joining Showroom to Makerin order to produce a report for managers, wishing to see which showrooms have whichfranchises. This shortcut join would not use the Rental or Sales contexts. Instead it wouldgo directly from Showroom to Maker, as the shortcut join takes precedence over any otherjoin.

However applying a shortcut join here is not possible due to the keys set up in the tables.A linking table between ShowroomandMaker, togetherwith a new context, will be requiredto return the same results.

Activity: Resolving loops with aliases

Objectives

• Resolve loops by creating alias tables• Test your results in Web Intelligence


Instructions

In this actvity you will add new tables, insert new joins, and set cardinality, that will createloops in the Motors universe. You will then resolve the loops and test them.1. Insert the following join and set its cardinality.

• COUNTRY.COUNTRY_ID=SHOWROOM.COUNTRY_ID

2. Use theDetect Loop toolbar button to test for loops in your universe. To solve the loopsthat you have detected by creating alias tables, press the Insert Aliases button in the LoopDetection dialog box, or use the Insert Alias toolbar button and create two alias tablescalled:• COUNTRY_SHOWROOM

• COUNTRY_REGION

3. Disconnect the original COUNTRY table from the other tables and use the alias tables toredefine the joins as follows:• COUNTRY_SHOWROOM.COUNTRY_ID=SHOWROOM.COUNTRY_ID

• COUNTRY_REGION.COUNTRY_ID=REGION.COUNTRY_ID

• COUNTRY_REGION.COUNTRY_ID=CLIENT.COUNTRY_ID

4. Set the new join cardinalities. In the third join, be sure to select the Shortcut join check box.

5. Create a Country object in the Showroom class with the settings:• Name = Showroom Country• Type = Character• Description = Country in which showroom exists• SELECT =

COUNTRY_SHOWROOM.COUNTRY_NAME

• Associate an LOV

6. Edit the Country object in the Client class as follows:• Name = Client Country• SELECT =

COUNTRY_REGION.COUNTRY_NAME

7. Check integrity by selecting the Check Integrity button in the toolbar.The check integrity tool finds divergences because the COUNTRY table is now isolated.Ignore this message and don’t delete the original table.


9. Test your changes inWeb Intelligence by building a query containing ShowroomCountry,Client Country, and Sales Revenue objects.

10.Edit the query and remove the Client Country, and Sales Revenue objects. Run the querywith just the Showroom Country object.


11.In Designer, create an additional alias of the COUNTRY table, calledCOUNTRY_MAKER.

12.Insert the following join:• COUNTRY_MAKER.COUNTRY_ID=MAKER.COUNTRY_ID

Make sure that the join cardinality is set to one-to-many (1-N).

13.Create aMaker Country object in the Car class.

14.Test your changes in Web Intelligence by building a query containingMaker Country,Maker, andModel objects.


Resolving loops using contextsAnother way to solve a loop in the universe structure is to create contexts.


• Describe contexts• Resolve loops using contexts

About contexts

A context resolves a loop by defining a set of joins that define one specific path through tablesin a loop. It ensures that joins are not included fromdifferent pathswithin the same SQL query.

You often use contexts in schema that contain multiple fact tables that share lookup tables.

An example of this situation is the Sale table in the Motors universe. The Sale table containsrows of data for cars both sold and rented. The Sale_Type column is used as a flag to indicatethe type of transaction (S = car sale, R = car rental).Without the self restricting join, the resultsetof the query would produce rows where the Sale_Type column is equal to either ‘S’ or ‘R’.

Previously, you defined this self-restricting join to ‘S’, so that any object based on the table orjoins passing through that table would produce query results covering only car sales.

In order to retrieve data concerning rental sales as well, you create an alias of the Sale tablecalled Rental, set the self-restricting join to ‘R’ and create an alias table of the Sale_Model tablecalled Rental_Model. Creating the aliases tables, however, will create a loop because the querywill not know which table to go through to get to the Model table, Sale or the alias Rental.

You can solve this type of loop by creating two contexts which will define the correct routethrough the universe structure. These routes link tables together in the structure.

What is a context?

A context is a list of joins that define a path for a query. The tables involved in the joins areincluded in the context.

Any objects derived from tables included in a context are compatible with each other. When aquery is made with objects related to separate contexts, more than one SELECT statement isinferred and run. The results of the queries are then merged in the microcube. This avoidsincorrect results that might arise due to a loop or other situation with alternative routes.

Alternative routes can exist without a loop in the universe structure.

Detecting and creating contexts

• A separate context is identified for each table with only the many end of joins attached.

• The joins in a context are identified by working back from the table with only the many endof joins attached - many-to-one, many-to-one.


Identifying the joins that make up a context

Designer detects contexts by identifying tables that have only the many ends of joins attached.It does this progressively throughout the structure.

No joins flowing back from one-to-many are included.

To help to see the flow of contexts within a structure, you can arrange the tables so that all thejoins flow as many-to-one from left to right across the structure.

Included in the context are all the tables that can be reached by following the flow frommany-to-one (N–1). Tables that can only be reached by flowing back from one-to-many (1-N)are not included in the context.

Note: If contexts are an important part of your universe structure, it can be very helpful toarrange your tables in this way, so that you can easily see the individual contexts.

When it is not appropriate to resolve a loop by using an alias to break the loop, the loop mustbe left in place. However, this results in an error message when running an end-user query.This is because there are two alternate routes around the structure. Contexts are used to specifythose alternate routes and ensure that a single inferred SELECT statement only includes referenceto columns from tables in one of those routes.

In the Sales and Rental example, you can follow two different paths from the Client table tothe Model table:• By way of Rental and Rental_Model:


• By way of Sale and Sale_Model:

Each context represents what may be inferred in a single SELECT statement.

Any query that infers some SQL code exclusive to one context and some exclusive to the otherwill infer two separate SELECT statements.


This loop can be resolved by two candidate contexts:

Sale_Model ContextRental_Model Context

COUNTRY.COUNTRY_ID=REGION.COUNTRY_IDCOUNTRY.COUNTRY_ID=REGION.COUNTRY_ID

REGION.REGION_ID=CLIENT.REGION_IDREGION.REGION_ID=CLIENT.REGION_ID

CLIENT.CLIENT.ID=SALE.CLIENT_IDCLIENT.CLIENT.ID=RENTAL.CLIENT_ID

SALE.SALE_ID=SALE_MODEL.SALE_IDRENTAL.SALE_ID=RENTAL_MODEL.SALE_ID

SALE_MODEL.MODEL_ID=MODEL.MODEL_IDRENTAL_MODEL.MODEL_ID=MODEL.MODEL_ID

MODEL.MODEL_PRICE betweenSALES_PRICE_RANGE.PRICE_RANGE_MIN andSALES_PRICE_RANGE.PRICE_RANGE_MAX

MODEL.MODEL_DAYRENT betweenRENTAL_PRICE_RANGE.RENT_RANGE_MIN andRENTAL_PRICE_RANGE.RENT_RANGE_MAX

Note: The name of the context is normally defined by the table with only the many (N) end ofjoins attached to it.

You then create different sets of objects from the tables in the different contexts. As a result,users can run either Sales queries or Rentals queries, dependent on the objects they select.

Note: Every join (except shortcut joins) must exist in at least one context.

Detecting and creating contexts

The table below shows the toolbar buttons you can use to detect and create contexts.

Loop detection tool suggests candidates forboth aliases and contexts.

Detect loops

Detect Contexts detects and proposes a list ofcontexts to create.

Detect contexts

Insert Contexts inserts a context manually.

Insert contexts


To detect contexts using the Loop Detection tool

1. Click the Loop Detection button in the Editing toolbar.

The system displays the Loop Detection dialog box.

The first loop is highlighted in the Structure pane, and the message tells you that this loopis not covered by any context. If other loops exist, click the forward arrow button to cyclethrough the loops. Each loop is highlighted in turn, and a method of resolution isrecommended.

2. Click the Candidate Context button to see what the tool suggests.

The Candidate Contexts dialog box displays.

3. Highlight the candidate context you want to add and click the Add button.

The context moves across to theAccepted Contexts field. You can click the Rename buttonto give each context a more meaningful name.

Note: You may choose to leave the original context name in brackets. This can be useful inorder to remind you that you have changed the joins in the context, while still allowing youto view the original definition.

4. Repeat the process until you have accepted all the candidate contexts.

Note: Each candidate context is highlighted in the structure as you highlight it in theCandidate Contexts field. This enables you to check the context before accepting it.

The Candidate Contexts dialog box closes, and the List Modewindow opens in the upperpart of the Structure pane.

5. ClickOK.


6. Close the Loop Detection dialog box.

The List Modewindow shows the created contexts.

The Joins pane indicates the joins that are involved in the currently highlighted context.The Structure pane highlights the tables that are involved.

7. When you have created the contexts you require to resolve the loops, save the universe.

To detect contexts using the detect contexts tool

1. Select Tools ➤ Automated Detection ➤ Detect Contexts , or click theDetect Contextsbutton.

The system may display this message:

You may have just set the cardinalities, but you can still get this message because ofself-restricting joins. The system does not set cardinality on these, and therefore displaysthis message. ClickOK to continue because you have set the cardinality for all of the joins.

2. ClickOK.

The system displays the Candidate Contexts dialog box.

3. Highlight the candidate context you want to add and click the Add button.

You move contexts across to theAccepted Contexts field. Rename them, if required, in thesame way as when using the Loop Detection tool.

4. Repeat the process until you have accepted all the candidate contexts.

5. ClickOK and save the universe.


To insert contexts manually

1. Click the Insert Contexts button.

TheNew Context dialog box appears.

2. Define a name to identify the context in the Context Name field.

3. Select the joins that define the path for the context by clicking the individual joins in theCurrent context join list. To remove a join from the selected list, click it again to removethe highlight.

Note: From the List Modewindow, you can open the Edit Context dialog box to add joinsby double-clicking the context in the Contexts pane.

4. When you have made a selection of joins, click the Check button to have Designer checkwhether there are any loops in the joins you have selected.

5. In theDescription field, enter the text that displays in the user moduleHelp field.

6. ClickOK to create the context and close the dialog box.

Creating objects for each context

When all the contexts are in place, you can create objects.

Some objects refer to tables that are included in only one of the contexts. In this example, suchobjects include Sales Revenue or Rental Revenue. Other objects refer to tables which appear inboth contexts. In this example, such objects include Client Name.

Editing a context

Sometimes, a user creates a query using objects that reference tables from opposite ends of twocontexts, for example, a query using Client Name and Model.

The Client and Model tables are on opposite sides of the Rental and Sales contexts.

As a result, there are two potential routes for the inference engine to use in the SELECT statementso, when the end users run the query, they receive a prompt message to choose one of thosecontexts.

As the term “context” is notmeaningful to end users, you need to ensure that the context namesand theHelp descriptions clearly indicate how the choice of context influences the results.

To edit the name and help description

1. Open theListModewindowby clicking theViewListMode button on the standard toolbar.

2. In the Contexts pane, double-click the context you want to edit.

The Edit Context dialog box displays.


TheContext Name shows the name you accepted (or altered) when you created the context.The Join List shows all the joins that are included in the context path. The highlighted joinsare included.

3. Scroll down the list of highlighted joins to verify that all required joins are included. Youcan add additional joins, or remove unnecessary joins.

4. Click theDescription field and enter a suitable explanation of the context’s purpose.

5. ClickOK to close the Edit Context dialog box.

6. Click the View List Mode button to close the List Modewindow.

7. Save the universe.The description that you entered appears in the Context Selection Help dialog box inBusiness Objects end-user querying tools, and the process of selecting a context is madeeasier for end users.

Testing contexts

Any end-user query that generates a SELECT statementwhich spans across the loop failswithoutcontexts in place. If contexts are in place, the end-user query tool generates the SELECTstatement(s) in one of three ways. To test contexts, make at least three queries, one to test eachform of SQL generation when applying contexts. The three query types are:• Inferred query

• Incompatible objects query

• Ambiguous query

Inferred query

A query is run without prompting an end user to choose a context. The query contains enoughinformation for the correct context to be inferred. For example, a user runs a query using theShowroom, Model and Sales Revenue objects.

When these queries are run, the data is returnedwithout prompting the user to select a context.The Sales Revenue object is a sum on the Sale_Model table, which is part of the Sales context.The query infers that the Sales context is the one to use for the query.

Incompatible objects query

Objects that reference tables with joins belonging to two different contexts are included in asingle query. The tool creates one SELECT statement for each context, executes the queries, andthen unites the results together so that the report data can be presented in a single table.

For example, if you run a query containing the Showroom, Model objects with both SalesRevenue andRental Revenue objects, no single context contains all the joins necessary to includethe Showroom, Sale, Sale_Model, Rental, and Rental_Model tables to which the three objectsrefer. It therefore generates two SELECT statements in the query and merges the results in asingle microcube report.

Note: For an incompatible objects query to work, you need two contexts.


Ambiguous query

An end user is prompted to choose between one query path or another. This occurs when aquery includes objects that, when used together, do not give enough information to determineone context or the other.

When a query is ambiguous, the user is prompted by a dialog box in theReport Panel to selectthe appropriate context. When the user selects a context, the corresponding tables and joinsare inserted into the SQL query.

For example, if you run a query containing only the Showroom and Model objects, more thanone context contains all the joins necessary to include the ShowroomandModel tables towhichthe two objects refer.

The user is prompted to identify which context to use by displaying the Context Selectiondialog box.

When the user selects one of the contexts and clicks OK, a SELECT statement is inferred usingthe join path for the context chosen.

Note: For a user to selectmore than one contextwhen running an ambiguous query, theAllowselection of multiple contexts option in the SQL tab of theUniverse Parameters dialog box inthe Designer module must be selected.

Updating contexts

Contexts are not updated automatically when the universe structure is changed. If you add orremove any tables or joins to the structure, you will have to update all the contexts.

If you have made only a simple change to the structure, you can update the joins that areincluded in each context manually using the Edit Context dialog box. However, if you have


made significant changes to the universe structure, it can be safer to remove the current contextsand recreate them.

Recommended sequence

It is always best to create all your alias tables first, and then create your contexts, because ofthe requirement to update contexts. Otherwise, your alias tables will not be included in yourpreviously created contexts.

For loop resolution, the sequence is as follows:1. Set cardinality on all joins.

2. UseDetect Aliases to detect all the loops that can be resolved with alias tables.

3. Insert all the required alias tables and their associated joins. Remember to set cardinality onany new joins.

4. UseDetect Contexts to detect all the contexts that can be used to resolve the remainingloops that could not be resolved with an alias.

5. Accept the candidate contexts, or create your own contexts manually.

The need to follow this sequence highlights the main drawback of using the Loop Detectiontool. If you detect all loops, and then follow the Loop Detection dialog box suggestions forresolving them in the order that they are presented, youwill not necessarily resolve all the aliastable loops first, followed by all the context loops. It is therefore better to use the alias detectiontool first, and then the context detection tool.

Remember also that you will have to redefine any objects that are based on tables for whichyou have created aliases. The overall sequence in universe design is therefore as follows:1. Add tables to the universe.

2. Insert joins.

3. Detect and resolve loops.

4. Create all the classes and objects.

Note: If you want to test your loop resolution in a query, you may need to create some basicobjects to allow you to run some simple queries. If you do this, always bear in mind the needto redefine them when you have finished resolving loops.

Activity: Resolving loops using contexts

Objective

• Resolve loops by using contexts.

Instructions

In this workshop you will add new tables, insert new joins, and set cardinality, that will createloops in the Motors universe. You will then resolve the loops using contexts, and test them.


1. In Designer, create the following aliased tables:• RENTAL (alias of SALE)

• RENTAL_MODEL (alias of SALE_MODEL)

2. Insert the table.• RENTAL_PRICE_RANGE

3. Insert the following joins and set their cardinality.

Joins

CLIENT.CLIENT_ID=RENTAL.CLIENT_ID

RENTAL.SALE_ID=RENTAL_MODEL.SALE_ID

RENTAL.SALE_TYPE='R'

RENTAL.SALE_DATE between FINANCE_PERIOD.FP_START and FINANCE_PERIOD.FP_END

RENTAL_MODEL.MODEL_ID=MODEL.MODEL_ID

SHOWROOM.SHOWROOM_ID=RENTAL.SHOWROOM_ID

RENTAL_MODEL.COLOUR_ID=COLOUR.COLOUR_ID

MODEL.MODEL_DAYRENT between RENTAL_PRICE_RANGE.RENT_RANGE_MIN and RENTAL_PRICE_RANGE.RENT_RANGE_MAX

4. View loops using the loop detection tool.

Tip: You should find 10 loops.

5. Resolve the loops by using the context detection tool.

6. Edit the RENTAL_MODEL context as follows:• Change the name of the context to RENTALS.• As a description for the context enter: "Returns information on cars rented".• Remove the following join from the context list:

MODEL.MODEL_PRICE between SALES_PRICE_RANGE.PRICE_RANGE_MIN and SALES_PRICE_RANGE.PRICE_RANGE_MAX

• Add the following self-restricting join to the context:RENTAL.SALE_TYPE='R'

7. Edit the SALE_MODEL context as follows:


• Change the name of the context to SALES.• As a description for the context enter: "Returns information on cars sold".• Remove the following join from the context list:

MODEL.MODEL_DAYRENT between RENTAL_PRICE_RANGE.RENT_RANGE_MIN and RENTAL_PRICE_RANGE.RENT_RANGE_MAX

• Add the following self-restricting join to the context:SALE.SALE_TYPE='S'

8. Create a class called Rentals above the Sales class.

9. Create the following subclasses in the Rentals class:• Rental Details• Rental Dates• Rental Figures

10.Create the following four objects in the appropriate subclass of the Rentals class:


Unique Invoice IDNumberRENTAL.SALE_IDInvoice ID Number

First day of RentalRENTAL.SALE_DATERental Date

Date rental car has been/ isto be returned

RENTAL.SALE_DATE +RENTAL.SALE_RENTAL_PERIODReturn Date

Total Rental Invoice Value

SUM(RENTAL.SALE_RENTAL_PERIOD*RENTAL_MODEL.SALE_QTY*

Rental Revenue MODEL.MODEL_DAYRENT*((100 - RENTAL.SALE_SALE_DISCOUNT)/100))

11.Create a subclass called Day Rental Charges in the Car class. Then populate the subclasswith the following objects.


Description of Rental Chargebanding

RENTAL_PRICE_RANGE.RENT_RANGEDay Rental Range

Standard Day Rental ChargeMODEL.MODEL_DAYRENTModel Day RentalCharge

12.Save and export the universe, then test the contexts used to resolve the loops by buildingthe following queries in Web Intelligence:


• Showroomdimension and SalesRevenuemeasure objects. The inferred SELECT statementfor this query should use the SALES context.

• Showroom dimension and Rental Revenue measure objects. The inferred SELECTstatement for this query should use the RENTALS context.

• Showroom dimension, Sales Revenue and Rental Revenue measure objects. This queryshould infer two SELECT statements, one for each context.

• Showroom, Model, and Maker dimension objects. With this query, a dialog box shouldappear asking which context to use.

13.Insert the table named FRANCHISE in the universe structure. Insert the joins specifiedbelow and set cardinalities.• SHOWROOM.SHOWROOM_ID=FRANCHISE.SHOWROOM_ID

• FRANCHISE.MAKER_ID=MAKER.MAKER_ID

14.Detect contexts using the method of your choice.

Tip: In this instance, it is unnecessary to remove existing contexts and redetect them as theyare not affected by the FRANCHISE table and its joins.

15.Create the following object in the Showroom class, and then use it in a query to test that thecontext has resolved the loop correctly.


Car manufacturers withwhich the showroom has acontracted dealership.

MAKER.MAKER_NAMEFranchises

16.Check the integrity of the Motors universe with all options except Cardinality checked.Resolve any relevant divergence.

17.Save the Motors universe and close it.

18.Open the Staff universe. You want to report on Managers and their staff.

19.Create a class called Employees.

20.Create an alias table of the EMPLOYEE table and rename it MANAGERS.Join the tables as shown below:


21.Create a Staff dimension object based on the EMPLOYEE table. Concatenate the EmployeeLast Name and First Name.

22.Create aManagers dimension object based on the alias MANAGERS table. Concatenate theManagers Last Name and First Name.

Tip: To get the query to infer the correct SQL, you will need to resolve the self-join in theuniverse structure.

23.Check the integrity of the Staff universe with all except the cardinality options checked.Resolve any relevant divergence.

Tip: You should not find any divergences.

24.Save and export the Staff universe.


Quiz: Resolving loops in a universe1. What is the first step in resolving loops?

2. What causes a loop?

3. What are the two main methods of resolving loops?

4. What are the three types of queries you can use to test your contexts?



• Understand loops• Resolve loops using shortcut joins• Resolve loops using aliases• Resolve loops using contexts



Lesson 8Resolving SQL Traps

Lesson introductionThis lesson deals with two common SQL Traps: Chasm and Fan. Chasm traps and fan trapsare problems inherent in SQL that are caused by the order in which the elements of the SELECTstatement are processed.


• Understand SQL traps and universes• Resolve fan traps• Resolve chasm traps

179Resolving SQL Traps—Learner’s Guide

Understanding SQL traps and universesIn order to avoid common SQL traps in your universe, it is important to understand howaggregates in queries may result in incorrect data.


• Explain how SQL traps can cause queries to return inaccurate results

About SQL traps

Chasm traps and fan traps are problems inherent in SQL that are caused by the order in whichthe elements of the SELECT statement are processed.

In SQL, a SELECT statement processes the SELECT, FROM, and WHERE clauses first (with the exceptionof any aggregates). In doing so, it creates a product of all the tables in the FROM clause on thebasis of the joins and restrictions specified in the WHERE clause. This can be thought of as avirtual table. Normally this does not cause a problem, but if an aggregate is applied then itmay, in particular circumstances, result in wrong output being generated. This is particularlyworrying because SQL does not produce an error message, it just projects the results.

Unlike loops that return fewer rows than expected, chasm traps and fan traps return too manyrows.

Fortunately, there are ways of identifying situations in which chasm traps and fan traps canoccur, and there are methods of resolving these situations.


Detecting and resolving chasm trapsThis unit explains how chasm traps can occur in the universe structure and how to resolvethem.


• Explain what a chasm trap is• Detect chasm traps in a universe structure• Resolve chasm traps

Chasm traps

A chasm trap is a common problem in relational database schemas in which a join path returnsmore data than expected.

A chasm trap is a type of join path between three tables when twomany-to-one joins convergeon a single table, and there is no context in place that separates the converging join paths.

You only get incorrect results when the following circumstances all exist simultaneously:1. There is a “many-to-one-to-many” relationship between three tables in the universe structure.

2. The query includes objects based on the two “many” tables.

3. There are multiple rows returned for a single dimension value.

For example, in this diagram there is no loop, but the flow around the three tables ismany-to-one-to-many.

Note: A chasm trap is not dependent on the object types. The query could be made up of onlydimensions, only details, or only measures, or any combination of the three types with the “many”tables for a chasm to occur.

When a query that uses objects Y and Z is run, the inferred SQL includes tables B, C, and Athat have a “many-one-many” relationship respectively. The chasm trap causes a query toreturn every possible combination of rows for one measure with every possible combinationof rows for the other measure. This results in the values for each object being multiplied by theother. The effect is similar to a Cartesian product but is known as a chasm trap.

The chasm trap is resolved by executing separate SELECT statements for object Y and object Z.


Detecting chasm traps

Unlike loops, chasm traps are not detected automatically byDesigner. However, you can detectthem in one of the following ways:• Analyze the one-to-many (1-N) join paths in your schema to detect chasm traps graphically.

• SelectTools ➤Detect Contexts or click theDetect Contexts button to automatically detectand propose candidate contexts in your schema.

Detect Contexts examines the many-to-one (–1) joins in the schema and proposes contextsto separate the queries run on the table. This is the most effective way to ensure that yourschema does not have a chasm trap.

• Add additional dimension or detail objects to display more information in the report. Ifthere is a chasm trap, aggregated values will be doubled, alerting you to the problem.

You can use Detect Contexts to detect and propose candidate contexts, and then examinethe table where any two contexts diverge. The point where two contexts intersect is thesource of a chasm trap.

Any two tables that have multiple rows converging to a single row in the table with the“one” relationship may potentially cause a chasm trap.

The Chasm trap scenario

This section demonstrates a chasm trap in the Motors universe, and proposes two solutions tothe problem.

In the diagram below, the Sale, Client and Rental (Sale) tables are joined by a“many-to-one-to-many” relationship.


The following objects in Motors reference the tables above:

In this scenario, the universe designer has not selected the “Multiple SQL statements for eachmeasure” option in the Universe Parameters SQL tab.

A user creates a series of queries using these objects and gets inaccurate results.


The first two queries return the correct data, but combining Sales Revenue and Rental Revenuein the third query returns inaccurate results.

To understand what is happening here, you need to examine the rows that are returned by thequeries to make the aggregated figures. In our example, you can do this by adding the SaleDate and Rental Date objects to the queries to return individual transaction details.

Notice that there are two sale transactions in the first table. There are also two rental transactionsin the second table.

If you add the dates to the combined query as in the third table, you can see why the sale andrental revenues have doubled.


The query returns every possible combination of sale rows with every possible combinationof rental rows. Hence, the sale transactions each appear twice as do the rental transactions, andas a result of this the aggregates have been multiplied by the number of related rows on thealternative ‘many’ table.

Where you have a many-one-many relationship for tables in the FROM clause, the resultinglogical table produces something akin to a Cartesian product. Only then is aggregation applied.This is the reason for the chasm effect.

The problem with chasm traps is that, unless you look at the detail rows, there is nothing toalert you to the situation.

Resolving chasm traps

To resolve a chasm trap, you need to make two separate queries and then combine the results.Depending on the type of objects defined for the fact tables and the type of end-userenvironment, you can use the following methods to resolve a chasm trap:• Modify the SQL parameters for the universe so you can generate separate SQL queries for

each measure.

This method is not recommended as it only works with measures and will result in certaininefficiencies in processing. It does not generate separate queries for dimension or detailobjects.

• Create a context for each fact table.

This solution works in all cases and will not result in inefficiencies.

Usingmultiple SQL statements for eachmeasure to resolve chasmtraps

If you have only measure objects defined for both fact tables, then you can use the UniverseParameters optionMultiple SQL statements for each measure. This forces the generation ofseparate SQL queries for each measure that is used in the query. It does not work for queriesthat do not contain measures.


With the optionMultiple SQL statements for eachmeasure selected, Designer will nowmakeseparate SQL SELECT statements for each measure object in the query.

The results in the report are now correct, as the query has automatically generated two SQLstatements.

Using this option will resolve the chasm trap problem. However, there are drawbacks to usingthis method to resolve chasm traps.

To activate multiple SQL statements for each measure to resolvechasm traps

1. Select File ➤ Parameters from the menu bar or click the Parameter button.The Universe Parameters dialog box appears.

2. Click the SQL tab.

3. Click theMultiple SQLStatements for EachMeasure check box in theMultiple Paths zoneto select this option.


4. ClickOK.


6. In Web Intelligence, create a new query using a dimension object, and two measure objectsfrom the “many-to-one-to-many” table relationship.

7. Run the query.

The results in the report are now correct, as the query has automatically generated two SQLstatements.

8. Access the SQL that is generated in the SQL Viewer by clicking the Edit Query button onthe toolbar to open the Report Panel.

9. Click on the View SQL button.

This will display the separate SQL Statements.

Drawbacks to the Multiple SQL statements for each measuremethod

Using theMultiple SQL statements for eachmeasure optionwill resolve the chasm trap problem.There are, however, two main drawbacks to using this method.

The results can be confusing.

The SQL Parameter used specifies: “Multiple SQL statements for each measure”. One of thedrawbacks is that it does not run separate SELECT statements if the query contains onlydimension objects.

The report contains a single block with the results displayed as a Cartesian product.


It is not that there is anything inaccurate about the dates, but the multiple occurrences will beconfusing to users.

The query is inefficient.

Another drawback is that any query including multiple measures will infer a separate SELECTstatement for each measure irrespective of whether it is required or not.

To find a complete solution to chasm traps, you must use contexts.

Using contexts to resolve chasm traps

You can define a context for each table at the many end of the joins. In this example you coulddefine a context from Client to Sale and from Client to Rental.


When you run a query that includes objects from both contexts, this creates two SELECTstatements that are synchronized at run-time in BusinessObjects end-user query tools to preventthe creation of a Cartesian product.

Creating contexts will always solve a chasm trap in a universe. When you have amany-to-one-to-many situation, always use a context.

To use contexts to resolve a chasm trap

1. Identify the potential chasm trap by analyzing themany-to-one-to-many join path relationsin the schema.

2. Select Tools ➤ Automated Detection ➤ Detect Contexts from the menu bar or click theDetect Contexts button.

The Candidate Contexts dialog box appears.

3. Select a proposed context in the Candidate Contexts list box and click Add to add it to theAccept Contexts list box.

4. Repeat for other listed contexts.The new contexts are listed in the Contexts pane of the List Viewwindow.

5. Select File ➤ Parameters from the menu bar or click the Parameters button.

The Universe Parameters dialog box appears.

6. Click the SQL tab.

7. Select theMultiple SQL for each Context check box to clear the option.

8. ClickOK.

When you run queries on the tables in the chasm trap, the query separates the SQL intowhat is compatible for separate SELECT statements.


Activity: Resolving chasm traps

Objective

• Detect contexts to resolve a chasm trap in the universe structure.

Instructions

1. Create a new universe called Chasm.unv.Use the Motors_conn connection to connect to the Motors database.

2. Select File ➤ Parameters from the menu bar or click the Parameter button and select theSQL tab.

3. Clear theMultiple SQL statements for each measure option by clearing the check box.

4. Add the following tables:• CLIENT

• SALE

• RENTAL (as an alias of the SALE table)

5. Create the following joins and set the cardinality:

CardinalityJoin

1:NCLIENT.CLIENT_ID=SALE.CLIENT_ID

1:NCLIENT.CLIENT_ID=RENTAL.CLIENT_ID

1:1SALE.SALE_TYPE='S'

1:1RENTAL.SALE_TYPE='R'

6. Create two classes: one called Chasm Objects, and the other calledMeasures.

7. Add the following objects with the following syntax:

QualificationSELECTObject


DimensionCLIENT.CLIENT_LASTNAME + ' , ' + CLIENT.CLIENT_FIRSTNAMEClient Name

DimensionSALE.SALE_DATESale Date

DimensionRENTAL.SALE_DATERental Date

MeasureSum(SALE.SALE_TOTAL)Sales Revenue

MeasureSum(RENTAL.SALE_TOTAL)Rental Revenue

8. Perform an integrity check on:• Check Universe Structure• Parse Objects• Parse Joins


10.InWeb Intelligence, create a newdocumentwith two “control” queries to display the correctsales and rental figures for Paul Brendt in the Chasm universe.• In the first query, use the Sale Revenue, and Client Name objects.

Select the Client Name object, and click the Apply a Quick Filter button. From the Listof Values, select Brendt, Paul.

• In the second query, use the Rental Revenue, and Client Name objects.

Select the Client Name object, and click the Apply a Quick Filter button. From the Listof Values, select Brendt, Paul.

11.Click Run Queries and view the results in the report.• What is the sale amount now?• What is the rental amount?

12.In the same report add a new table by clicking the Edit Query button. Click Add Query,and create a new query using the Sale Revenue,Rental Revenue, andClient Nameobjects.Select the Client Name object, and click the Apply a Quick Filter button. From the List ofValues, select Brendt, Paul.

13.Click View SQL to check the SQL statement generated.

14.Click Run Queries and select the Insert a table in the current report option.• What is the sale amount in the new table?• What is the rental amount in the new table ?• What happened to your figures?

15.Log out of Web Intelligence.


16.In Designer, edit the universe by clicking File ➤ Parameters ➤ SQL tab, and select theMultiple SQL statements for each measure option.


18.InWeb Intelligence, create a new document using the Sale Revenue ,Rental Revenue, andClient Name objects. Select the Client Name object, and click the Apply a Quick Filterbutton. From the List of Values, select Brendt, Paul. Click View SQL to check the SQLstatement generated.• What is the sale amount?• What is the rental amount in the new table ?• What happened to your figures?

19.Edit the query by clicking the Edit Query button on the toolbar.

20.Remove theSales Revenue, and theRental Revenue objects. Drag theSaleDate, andRentalDate objects into the Report Panel. Click Run Query.• What happens to the SQL and to the results?


22.In Designer, edit the universe by clicking File ➤ Parameters ➤ SQL tab and clear theMultiple SQL statements for each measure option again (clear the check box).

23.Insert the following contexts:

JoinsContext

CLIENT.CLIENT_ID=SALE.CLIENT_ID

SALE.SALE_TYPE='S'Sale

CLIENT.CLIENT_ID=RENTAL.CLIENT_ID

RENTAL.SALE_TYPE='R'Rental


25.In Web Intelligence, create a new query with the Client Name, Sales Revenue, and RentalRevenue objects. Select the Client Name object and click the Apply a Quick Filter button.From the List of Values, select Brendt, Paul.• What is the sale amount?• What is the rental amount?• What happened to your figures?


Detecting and resolving fan trapsThis unit explains how fan traps can occur in the universe structure and how to resolve them.


• Explain what a fan trap is• Detect fan traps in the universe structure• Resolve fan traps

Fan traps

Fan traps occur when there is a “one-to-many” join to a table that “fans out” into another“one-to-many” join to another table.

This is a common structure and will not normally result in a fan trap. You only get incorrectresults from the fan trap when the query includes a measure object on the middle table (B) ofthe table path and an object (of any kind) from the subsequent table (C). The trap only occurswhere (due to the database design) a column in table B holds data values which are already asum of those values held at table C. The results are normally noticeably wrong.

When a query is run using objects Y and Z, the inferred SQL includes tables B and C whichhave a ‘one-to-many’ relationship. This results in a value for the Y object being multiplied bythe number of values of the Z object related to that Y object value. Like the chasm trap, theeffect is similar to a Cartesian product.

Like the chasm trap, the fan trap can be resolved by executing a separate SELECT statement forobject Y and object Z. The alternate solution is to avoid it in the first place.

You cannot automatically detect fan traps. You need to visually examine the direction of thecardinalities displayed in the table schema.

If you have two tables that are referenced by measure objects and are joined in a series of“many-to-one” joins, then you may have a potential fan trap.


The fan trap scenario

This section demonstrates a fan trap in the Motors universe, and proposes solutions to theproblem.

In the diagram below, the Client and Sale tables are joined by a “many-to-one-to-many”relationship, as are the Sale and Sale_Model tables.

The fan trap problem becomes apparent in a query that aggregates both an object based on theSale_Total column in the Sale table, and an object based on the Sale_Qty column in theSale_Model table.


What happens in the fan trap

When you run the Test 1 query to report the Sales Revenue for a client, the measure is correctlyaggregated. This is a simple aggregate from one table in the fan trap structure. However, ifyou also wanted to know the number of vehicles the client has purchased, and you includedthe Number of Cars Sold object in the query, you get an inflated value returned for SalesRevenue.

To understand what is happening, you need to look at the rows that are returned. Since twodifferent Model ID numbers are involved in the Sale Quantity (Number of Cars Sold), thereare two rows returned.

As with chasm traps, a single SELECT statement joins each Model ID row with the same SalesRevenue row, which gives you the doubled figure.

There is nothing to alert you to the situation, unless you look at the detail rows.

Where you have a one-many-many relationship for tables in the FROM clause, the resultinglogical table produces something akin to a Cartesian product. Only then is aggregation applied.This is the reason for the fan effect.

Resolving fan traps

The recommended ways to solve a fan trap problem are:• Alter the SQL parameters for the universe.• Use a combination of aliases and contexts.• Avoid the fan trap scenario.

Alter the SQL parameters for the universe

This method is not recommended as it only works for measure objects and may result ininefficiencies in processing the query. This resolution works the same for chasm and fan traps.

Use a combination of aliases and contexts

There are two possible situations which may require different solutions.

Then...If you have...

Create an alias for the table (on the many end of the join)containing the initial aggregation, joining it back to the

• Three tables in a one-to-manyrelationship

• A dimension coming fromthe first table and measures

non-aggregation table (on the one end of the join). Use theDetect Contexts tool to detect and propose a context for thealias table and a context for the original table.


Then...If you have...

This is the most effective way to solve the fan trap problembecause it works with measure and dimension objects anddoes not cause inefficiencies.

coming from the twosubsequent tables

Create an alias for the table containing the initial aggregation,joining it back to the original table and then use the Detect

• Two tables in a one-to-manyrelationship

• A dimension and a measurecoming from the first table

Contexts tool to detect and propose a context for the aliastable and a context for the original table.

and a measure coming fromthe subsequent table(s)

Both of these methods solve the fan trap problem becausethey will work with both measure and dimension objectsand do not cause inefficiencies. You will explore both in thefollowing sections.

Note: However, to bemore efficient still, using the two-table scenario,you could also use the @aggregate_aware function.

Avoid the fan trap scenario

You can avoid the scenario in the first place by relating all measure objects in the universe tothe same table in the universe structure. Avoid placing a measure on anything other than thelast table in a table path, which is the table with the “many” cardinality attached to it.

Using aliases and contexts to resolve fan traps

You create an alias table for the table producing the aggregation and then detect and implementcontexts to separate the query. This procedure is demonstrated in the diagram below:

In this scenario your schema would look similar to:


The SELECT clause of the Sales Revenue object needs to be edited, so that it refers to the aliastable rather than the original Sale table.

As with resolving a chasm trap problem, two contexts need to be created. In this example, acontext for Sale, and a context for Sale_Model needs to be defined. This allows for the resultsto be merged into a single microcube to produce the correct results.

Moreover, if you make a query which includes a dimension object on the lower table in the‘one-many-many’ path, you will not suffer the fan trap, even when that dimension objectcontains the same value for all rows related to the measure value. The fact that the measureand dimension objects are in separate contexts forces two separate SELECT statements, thusavoiding the problem.

To use aliases and contexts to resolve a fan trap

1. Identify the potential fan trap by analyzing the one-to-many-to-one-to-many join pathrelations in the schema.

2. Create an alias for the table that is producing the multiplied aggregation.

3. Create a join between the new alias table, and the table that holds the dimension information.

4. Set cardinality.

5. Set contexts.

6. Change the SELECT clause of the measure object so that it refers to the alias table rather thanthe original table.


7. Create a query using a measure object from the alias table and another measure from thesubsequent table in the table path of the universe structure.

This results in two SELECT statements and the data is merged into a single microcube toproduce the correct results.

Solving a fan trap with two tables in a one-to-many relationship

The structure shownhere involves two tables instead of three. In this example, both a dimensionand measure object are from the same table, and another measure is from a table in aone-to-many relationship further along the universe structure.

To resolve this type of fan trap, you can:1. Create an alias of table A.

2. Create a join from the alias An to table A and set cardinalities.

3. Set contexts B and A.

4. Edit object Y so that it refers to columns in the alias An rather than table A.

In the universe structure shown below, you have created an alias table of the Sale table andcreated a join between the alias and the original table. This is to separate the dimension in Salefrom the measure, which will now refer to Sale_Alias.


To use aliases and contexts to resolve a fan trap

1. Identify the potential fan trap by analyzing the one-to-many-to-one-to-many join pathrelations in the schema.

2. Create an alias for the table that is producing the multiplied aggregation.

3. Create a join between the new alias table, and the table that holds the dimension information.

4. Set cardinality.

5. Set contexts.

6. Change the SELECT clause of the measure object so that it refers to the alias table rather thanthe original table.

7. Create a query using a measure object from the alias table and another measure from thesubsequent table in the table path of the universe structure.

This results in two SELECT statements and the data is merged into a single microcube toproduce the correct results.

Avoiding fan traps altogether

In certain situations, it is possible to avoid the fan trap completely, as shown in the diagrambelow.

To avoid the trap, the database column in table B to which the Y measure object relates mustrepresent a preaggregation of more detailed data in table C. If this is the case, you can change


the code of the Y measure object so that it refers to table C. Hence, there is no longer a‘one-to-many’ relationship incurred.

This is the method used to avoid the fan trap in the Motors universe, when the Sales Revenueand Number of Cars Sold measure objects are included in the same query.

In the Motors universe you have created during this course, the Sales Revenue measure is notbased on the total figure in the SALES table but on a number of columns from the Sale,Sale_Model and Model tables which are held in the database at the same level of granularityas the number of cars sold. Hence, no fan trap exists and the correct result will be obtained.

Note: Anothermethod of resolving a less common formof fan trap is by usingAggregateAwareness.


Activity: Resolving fan traps

Objective

• Detect contexts to resolve a fan trap in the universe structure.

Instructions

1. Create a universe called Fans.unv.Use theMotors_conn connection to connect to the Motors database.

2. Select File ➤ Parameters from the menu bar or click the Parameter button and select theSQL tab.

3. Clear theMultiple SQL statements for each measure option by clearing the check box.

4. Add the following tables:• CLIENT

• SALE

• SALE_MODEL

5. Create the following joins and set the cardinality:

CardinalityJoin

1:NCLIENT.CLIENT_ID=SALE.CLIENT_ID

1:NSALE.SALE_ID=SALE_MODEL.SALE_ID

1:1SALE.SALE_TYPE='S'

6. Create a class called Fan Objects.

7. Add the following objects with the following syntax:



DimensionCLIENT.CLIENT_LASTNAME + ' , ' + CLIENT.CLIENT_FIRSTNAMEClient Name

DimensionSALE_MODEL.MODEL_IDModel ID

MeasureSum(SALE_MODEL.SALE_QTY)Sale Quantity

MeasureSum(SALE.SALE_TOTAL)Sales Revenue

8. Perform an integrity check on:• Check Universe Structure• Parse Objects• Parse Joins


10.In Web Intelligence, create a new document using the Sales Revenue and Client Nameobjects. Select the Client Name object and click the Apply a Quick Filter button. From theList of Values, select Crandall, Sean.

11.Click Run Query and view the results in the report.• What is the sale amount?

12.Edit the query and add the Sale Quantity object.• What is the sale amount now?• What is the sale quantity?


14.In Designer, edit the universe by clicking File ➤ Parameters ➤ SQL tab and select theMultiple SQL statements for each measureoption.


16.In Web Intelligence, create a new document using the Sales Revenue, Sale Quantity, andClient Name objects. Select the Client Name object and click the Apply a Quick Filterbutton. From the List of Values, select Crandall, Sean.

17.Click Run Query and view the results in the report.• What is the sale amount?• What is the sale quantity?

18.Edit the query and add the Model ID object.• What is the total sale amount?• What is the total sale quantity?• How many different models were purchased?• What happened to your figures?


Tip: To retrieve the sumvalue, highlight the relevantmeasure columnwithout highlightingthe header, and select the Insert Sum toolbar icon.


20.In Designer, edit the universe by clicking File ➤ Parameters ➤ SQL tab and clear theMultiple SQL statements for each measure option by clearing the check box. Select theMultiple SQL statements for each context option if it is not already selected.

21.Add an alias to the SALES table (SALES2).

22.Create the following joins:

CardinalityJoin

1:NCLIENT.CLIENT_ID=SALE2.CLIENT_ID

1:1SALE2.SALE_TYPE='S'

Note: Force the cardinality on CLIENT.CLIENT_ID=SALE2.CLIENT_ID join to 1:N.

23.Use theDetect Contexts button to detect contexts.Be sure you have the following contexts. You may have to edit the context by removing oradding joins.

JoinsContext

CLIENT.CLIENT_ID=SALE.CLIENT_ID

SALE.SALE_ID=SALE_MODEL.SALE_ID

SALE.SALE_TYPE='S'

Sale Model

CLIENT.CLIENT_ID=SALE2.CLIENT_ID

SALE2.SALE_TYPE='S'Sale2

24.Modify the definition of the object that is performingmultiple aggregations so that it pointsto the alias table:


MeasureSum(SALE2.SALE_TOTAL)Sale Revenue


26.In Web Intelligence, create a new document using the Sales Revenue, Sale Quantity, andClient Name objects. Select the Client Name object and click the Apply a Quick Filterbutton. From the List of Values, select Crandall, Sean .

27.Click Run Query and view the results in the report.


• What is the total sale amount?• What is the total sale quantity?• How many different models were purchased?• What happened to your figures?


Quiz: Resolving SQL traps1. A chasm trap can occur when:

2. Describe two ways to resolve chasm traps.

3. Describe three ways to resolve fan traps.



• Understand SQL traps and universes• Resolve fan traps• Resolve chasm traps


Lesson 9Applying Restrictions on Objects

Lesson introductionThis lesson will help you understand and use restrictions, which are conditions in SQL that setcriteria to limit the data returned by a query.


• Restrict the data returned by objects

207Applying Restrictions on Objects—Learner’s Guide

Restricting the data returned by objectsA restriction is a condition in SQL that sets criteria to limit the data returned by a query.

You define restrictions on objects to limit the data available to users. Your reasons for limitinguser access to data depend on the data requirements of the target user. A user may not needaccess to all the values returned by an object. You might also want to restrict user access tocertain values for security reasons.


• Define data restrictions• Apply data restrictions to objects• Apply data restrictions using condition objects• Apply restrictions to tables• Apply data restrictions using the Tables button• Apply each type of restriction

Defining data restrictions

The WHERE clause in an SQL statement restricts the number of rows that are returned by thequery.

So far in your universe design work, the WHERE clauses have only been populated by the joinsyou made between the tables in the Structure pane.

The joins restrict the resultsets, usually based on equality between tables and prevent Cartesianproducts.

You can also use the WHERE clause to further restrict the data that is returned in a query incircumstances where you may want to limit certain users to query on a subset of the data.

For example, the report below is an unrestricted block containing data for Clients from allCountries:


The WHERE clause for the query is created from the SQL inferred from the joins made in theStructure pane:WHERE (COUNTRY_REGION.COUNTRY_ID=REGION.COUNTRY_ID) AND (REGION.REGION_ID=CLIENT.REGION_ID) AND (SALE_MODEL.MODEL_ID=MODEL.MODEL_ID) AND (SALE.SALE_ID=SALE_MODEL.SALE_ID) AND (CLIENT.CLIENT_ID=SALE.CLIENT_ID) AND (SALE.SALE_TYPE='S') AND (SALE.SALE_DATE between FINANCE_PERIOD.FP_START and FINANCE_PERIOD.FP_END)

Compare this with the following report, which is a restricted block containing data only forclients from the United Kingdom:

The WHERE clause for the query now has an extra line at the bottom. This is the restriction addedby the designer that limits the return of data to UK Clients:WHERE (COUNTRY_REGION.COUNTRY_ID=REGION.COUNTRY_ID)AND (REGION.REGION_ID=CLIENT.REGION_ID) AND (SALE_MODEL.MODEL_ID=MODEL.MODEL_ID) AND (SALE.SALE_ID=SALE_MODEL.SALE_ID) AND (CLIENT.CLIENT_ID=SALE.CLIENT_ID) AND (SALE.SALE_TYPE='S') AND (SALE.SALE_DATE between FINANCE_PERIOD.FP_START and FINANCE_PERIOD.FP_END) AND (COUNTRY_REGION.COUNTRY_NAME = 'United Kingdom'

Methods of restricting data in end-user modules

Within the design of a universe, you can either:• Force restrictions, which the end user cannot override: Object, Table, Conditional SELECT,

Additional Joins

• Provide optional restrictions, which the end user can choose to apply: Condition Objects

Remember that users can apply conditions themselves by way of the Report Panel. Therefore,avoid creating optional restrictions that are of a simple nature, as the end user should be capableof creating such conditions for themselves on a query-by-query basis.

There are often problems associated with inferred restrictions, as will become evident duringthis module. You are therefore advised only to force restrictions where they are absolutelynecessary.

To ensure that a restriction is always inferred when a particular object is used in an end-userquery, place the restriction in theWhere box of theDefinition tab in the Edit Properties dialogbox related to the object. You can do this when you create the object or you can add it later.


To apply a restriction to an object

1. Open the Edit Properties dialog box for the object and select theDefinition tab.

2. Enter the restriction directly in theWhere field, or via the Edit Where Clause dialog boxby selecting the >> button.

3. ClickOK.

When you have created or edited your object to include a restriction, you should test it byrunning a new query using a BusinessObjects end-user query tool. Always view the inferredSQL to check whether the SELECT statement includes the restriction in the WHERE clause andhas the desired effect. Remember to save your universe and export your universe beforedoing this.

The inferred SQL displays the restriction. The last line of the WHERE clause is taken from theobject restriction.

Drawbacks to applying restrictions to objects

Only create restrictions against objects when it is absolutely necessary.

For example, consider the situation where users of Motors need to make queries of only thosecars that can be rented. The only distinguishing factor in the underlying Motors databasebetween cars that can be rented and those that are stocked for sale is that theModel.Model_Dayrent column contains data for rental cars and is null for sale-only cars. Tocreate an object to list cars for rental, the object would have to include the restriction:Model.Model_Dayrent is not null.

If it is not necessary, do not create the restriction.

To see why, consider the implications of creating a UK Clients object as illustrated:


The drawbacks are as follows:• You would get a confusing proliferation of objects for end users because you would then

need a French Clients object, a German Clients object, and so on.

• As these objectswould all represent alternate restrictions, youwould not be able to constructa logical default hierarchy, which end users make use of when drilling down.

• Although the UK Clients example is fairly clear, in many cases the restriction will not beobvious to the user simply from the name of the object: the details of the WHERE clause arenot shown in the end-user interface.

• If two ormore similarly restricted objects are included in the same query, the conflict betweenthe WHERE clauses will cause no data to be returned.

Consider the situation if a user wanted data for UKClients andUS Clients. Youmight thinkthat including both the UK Clients and US Clients objects would meet that need. However,the inferred SQL for the query would include the following two lines:

AND (CLIENT_COUNTRY.COUNTRY_NAME = 'United Kingdom') AND (CLIENT.COUNTRY.COUNTRY_NAME = 'USA')

As no country satisfies both these conditions, no data is returned.

An alternative to applying restrictions to objects

There is an alternative to applying restrictions to objects without using WHERE clauses. Youwillstill have multiple objects, but you will avoid the conflicts that affect the return of data inqueries.

Thismethod involves using a conditional SELECT clause for the object instead of a WHERE clause.


For example, if you want to force users to select financial results by year, you could create aseries of Sales Revenue objects (one for each year). Each object would be edited, starting fromthe standard sum aggregate used in the basic Sales Revenue SELECT statement:

You would apply the condition for each year using the database function that applies IF THENELSE logic.

For Sales Revenue 2003, the SELECT statement would look like this:

Note: The Else value 0 is optional.

For Sales Revenue 2004, the SELECT statement would look like this:

Note: Many databases support the CASE function. Consult the documentation provided by yourdatabase vendor to see what types of conditional functions are supported.

After you have created or edited the objects, test them individually and together in a singlequery. When you view the SQL to check whether the inferred SELECT statement includes theconditional SELECT syntaxes, the SQL appears as follows:

When the query is run, the report looks similar to this:


The conditional SELECT statements have removed the problem of the conflicting WHERE clauses.The data correctly shows the 2003 and 2004 Sales Revenue for each client.

Restrictions using condition objects

A condition object, or predefined query filter, is a preset restriction created in Designer that auser can choose whether or not to apply to a query.

When users create queries they can create their own query filters to limit the data returned bythe query. They can also use the predefined query filters that the universe designer may havebuilt into the universe to make it easier for them to restrict the data.

In Web Intelligence, the predefined condition objects built into the universe can be viewed inthe Report Panel Data tab, identified as predefined query filters.

For example, if the designer has created condition objects for French Clients and UK Clients,the Predefined Conditions tab would contain these condition objects:

When you have created a condition object, test it in Web Intelligence by making a query thatuses the filter. View the SQL to check that the inferred SELECT statement includes the restrictionin the WHERE clause and has the desired effect.

The advantages of using condition objects

• Useful for complex or frequently used conditions

• Gives users the choice of applying the condition

• No need for multiple objects

• Condition objects do not change the user view of the dimension objects in the Classes andObjects tab in the Web Intelligence Report Panel


To create a condition object

1. In Designer, select the Filter option button at the bottom of the Universe pane.

The Universe pane changes to show the Condition Object View.

Note: Objects are not shown in the Condition Object View, but classes are. You add acondition object to a particular class. Also, be aware that deleting a class in the ConditionObject Viewwill delete that class from the whole universe, not just from this view.

2. Click the class in which you want to place the condition object.

3. There are two ways you can insert a condition:• Select the Insert Condition on the Editing toolbar.

• Right-click the class and choose Condition from the drop-down menu.

This opens the Edit Properties dialog box for condition objects.

4. In theName field, enter a name for the condition object.

5. In theDescription field, enter a help message for users describing the condition and anyeffect it will have on queries they make.

6. Enter the condition directly in theWhere field or via the Edit Where Clause dialog box byselecting the >> button.

7. ClickOK.

8. Save and export the universe.The newpredefined condition object built into the universe can be viewed inWeb Intelligencein the Report Panel Data tab.

Applying restrictions using the tables button

If a table in your database has a flag that is used to switch between two or more domains, youcan use this to apply restrictions at the table level.

For example, the Sale table in the Motors database has a column called Sale_Type, which isused to distinguish between sales transactions and rentals transactions. The flag is set to S forsales or R for rentals.

If you do not apply any restriction to this table, users running queries for sales (with appropriateobjects) will get a resulting report that includes data on rentals as well as sales. Therefore, theresults will be wrong.

You can apply a restriction to this table using a self-restricting join.

The self-restricting join appears as a stub join in the Structure pane:


The expression in the Edit Join dialog box is set as follows:

With this restriction in place, the data returnedwill be restricted to sales data, nomatter wherethe table is used in the inferred SQL.

For example, if the Sale table appears only in the FROM clause of the SQL, the restriction willstill be applied in the WHERE clause.

This is the main advantage of applying restrictions at the table level.

A lookup table in a database can be used to provide a description for more than one dimensionfrom a database.

For example, in the Motors database, the Country table contains a single list of countries, butthese include the country fromwhich clients come, the countrywhere a car showroom is located,and the country where a car maker is located.

As a designer, you can create objects from the Country table for use in the Client class (for theClient Country), in the Car class (for the car Maker Country), and in the Showroom class (forthe ShowroomCountry). We have done this in previous lessons and avoided loops by creatingthe appropriate alias tables.

If a user ran a query to answer the question: “Which countries do our showrooms exist in?”,youmight think that a simple query using only the ShowroomCountry object in the Showroomclasswould provide the answer. However, in the current universe, such a querywould actuallyinfer SQL that returns all countries held in the Showroom_Country table.SELECTSHOWROOM_COUNTRY.COUNTRY_NAME

FROMSHOWROOM_COUNTRY

To solve this problem, the ShowroomCountry object in the Showroom class must be restrictedso that it returns only country data relating to showrooms.

This is done by specifying that whenever the Showroom Country object is used in a query, theShowroom table must also be inferred in the FROM clause of the SELECT statement. Providingthat the Showroom_Country table is joined to the Showroom table (by intervening tables) using


only equi-joins, the object is then guaranteed to only return countries in which showroomsexist.

To restrict data by adding tables to the object definition

1. Double-click the object you want to restrict.

The Edit Properties dialog box for the selected object displays.

2. Click the Tables button.

The Tables dialog box appears.

3. Scroll down the list of tables until you can see the table that is already highlighted.

4. Hold down the Ctrl key and click an additional table to force joins between the selectedtables.

5. ClickOK to close the Tables dialog box.

6. Click Apply in the Edit Properties dialog box.

7. ClickOK.

Applying each type of restriction

Apply restrictions to objects when you need to force a restriction on users. However, a forcedrestriction is not automatically inferred whenever the table is included in the SQL. Be awareof the drawbacks of multiple objects and conflicting restrictions. Use conditional SELECTstatements instead.

Use condition objects when you want to assist users by providing optional filters, and when itis important to avoid multiple objects and changes to the Classes and Objects view.

Use self-restricting joins to apply restrictions to tables when you want the restriction to apply,irrespective of where the table is used in the SQL. This method is ideal when a table uses a flagto switch between two or more domains.

Use additional joins when a lookup table serves more than one purpose in the universe. Thismethod ensures that the user gets the correct answer to the question behind the query.

Activity: Applying restrictions

Objective

• Apply enforced restrictions to objects and tables and create optional restrictions usingcondition objects.

Instructions

The sales staff of Prestige Motors needs to drill from Day Rental Range through Model DayRental Charge to Model for Rental to deal with queries from potential customers.


1. Create aModel for Rental dimension object in the Day Rental Charges subclass.This object will have the same SELECT properties as theModel object.

2. Add a WHERE restriction to theModel for Rental object so that onlymodels available for rentare returned. The restriction is:MODEL.MODEL_DAYRENT IS NOT NULL

3. Create a US Clients dimension object in the Client class below the Client Name object withthe settings:• Type = Character• Description = Returns only data for clients in the USA• Select syntax:

CLIENT.CLIENT_LASTNAME + ', ' + CLIENT.CLIENT_FIRSTNAME

• Where syntax:COUNTRY_REGION.COUNTRY_NAME = 'USA'

4. Create another object in the Client class for UK Clients.

5. Save and export the universe, then test the two new Client objects in Web Intelligence:• Build a query containing UK Clients, US Clients, and Sales Revenue objects

The query returns no data because of the conflict of restrictions.

6. In Designer, create a new subclass below the Sales class called Annual Revenue. Populateit with separate Sales Revenue measure objects for the calendar years 2003 and 2004 asindicated below. Use the CASE function to do this.• 2003 Sales Revenue• 2004 Sales Revenue

7. In the Annual Revenue subclass create two separate Sales Revenue measure objects relatedto financial years FY03-04 and FY04-05 as indicated below. Use the CASE function to do this.• Sales Revenue for FY03-04• Sales Revenue for FY04-05

8. Save and export the universe, then test the two new calendar year Sales Revenue objects inWeb Intelligence:• Build a query containing Showroom, 2003 Sales Revenue, and 2004 Sales Revenue objects.• Replace 2003 Sales Revenue and 2004 Sales Revenue objects with the objects related to

financial years FY03-04 and FY04-05, instead of calendar years.

9. Remove the US and UK objects in the Client class that you just created, and create thefollowing condition objects instead:• A condition object for US Clients• A condition object for European Clients (excluding UK; UK clients are part of the Other

Clients condition object)• A condition object for Other Clients


10.Save and export the universe and test each restriction by building a query inWeb Intelligence.

11.Run a query using Showroom Country to see the list of countries that have showrooms.

12.In Designer, edit the properties of the Showroom country object by adding the Showroomtable to the list of tables associated with the object. Use the Tables button in the EditProperties, Definition tab of the object to do this.


14.In Web Intelligence, run the above query again and compare the results.

15.In Designer, ensure that the Client Country object will only return the countries in whichclients exist, whichever query is run. Do this by adding the Client table to the list of tablesassociated with the object.

16.Edit the Maker Country object in the same way, to ensure that it only returns the countriesin which car makers exist.

17.Edit the Franchise object so that it automatically infers the FRANCHISE context instead ofprompting the user to choose among the SALES, RENTALS and FRANCHISE contexts. Thisallows end users to report on the franchises and their location regardless of sales or rentalsinformation.Use the Tables button to highlight the MAKER and FRANCHISE tables.

18.Check the integrity of the universe.



Quiz: Applying restrictions on objects1. What is a restriction?

2. Explain two drawbacks of using restrictions at the object level.

3. When should you use self-restricting joins?



• Restrict the data returned by objects


Lesson 10Using @functions with Objects

Lesson introductionThis lesson will help you use the @functions to provide more flexible methods for specifyingthe SQL for an object.


• Use @functions

221Using @functions with Objects—Learner’s Guide

Using @functionsThe @functions are located in the Functions panel of the Edit Select Statement and in the EditWhere Clause dialog boxes for objects.


• Define @functions• Use the @prompt function• Use the @select function• Use the @where function• Describe the @aggregate_aware function

Defining @functions

In the Edit Properties dialog box of an object, if you look in the Functions panel of either theEdit Select Statement dialog box or the Edit Where Clause dialog box, you will find a list of@functions.

The most commonly used @functions are:• @prompt(,,,,)

• @select()

• @where()

• @aggregate_aware(,)

These functions can be applied in the Select and/orWhere dialog boxes of objects.

Can be used in...@function

Both Select and Where clauses@prompt

Only to be used in Select clauses@select

Only to be used in Where clauses@where

Only to be used in Select clauses@aggregate_awar

The @functions are used to provide flexible methods of specifying SQL.

@prompt

The @prompt function is used by the designer to force the end user to enter a value for arestriction when a query is run which includes the object in which the @prompt is specified.

This is done by placing a restriction based on the @prompt in the Where field of the EditProperties dialog box of an object. When the user runs a query including that object, a promptdialog box appears requesting a value to be entered.

It can be useful when you want to force a restriction in the inferred SQL but do not want topreset the value of the condition. For example:


In the example, the object Model for Rental is to be used by a salesman to list the models thatcan be rented. However, different models are rented from different showrooms. Hence, youwould want to restrict the returned list to cars rented from a single showroom. If you hardcoded the restriction, you would need a separate object for each showroom in the universe.Using the @prompt, you need only one.

@prompt syntax

The @prompt syntax consists of five parameters, separated by commas:• Prompt• Data Type (A, N, or D)• LOV pointer or hard-coded list• Mono or Multi• Free or Constrained

The first two parameters are mandatory, and the last three are optional. However, if you leaveout a parameter, you must still include the required commas. For example:SHOWROOM.SHOWROOM_Name = @prompt('Enter Showroom Name','A', 'Showroom\Showroom', Mono, Constrained)

Note: The first three parameters must be inside single quotes.

Prompt

This is the text, or question, that appears in the prompt dialog box when the query is run. Thetext must be enclosed in single quotes.


Data Type

Data type refers to a character to specify the type of data that will be returned:

'A for Alphanumeric

'N' for Numeric

'D' for Date

The specified character must be enclosed in single quotes.

List of Values (optional)

There are two methods of specifying a List of Values:• A hard-coded list:

Each value is separately enclosed in single quotes and separated by a comma, and thewholelist is enclosed in curly brackets. For example:{'Australia', 'France', 'Japan', 'United Kingdom', 'USA'}

• A pointer to a list of values from an existing object:

This can be invoked by double-clicking the object whose List of Values you want to use intheClasses andObjects pick list. This gives the Class name and the Object name, separatedby a back-slash. It must be enclosed in single quotes. For example:'Client\Country'

Mono or Multi (optional)

• Mono: Allows the user to select or enter a single value from the List of Values.

• Multi: Allows the user to select or enter multiple values from the List of Values.

Free or Constrained (optional)

• Free: Users can enter a value of their own, or pick one from the List of Values.

• Constrained: Users can only choose a value from the List of Values.

@select

The @select function is a pointer to the Select dialog box properties of another object. It is usedby placing the @select in the Select field of the Edit Properties dialog box of an object, usingthe following syntax:@select(path of existing object)

You specify the path in the form Class_Name\Object_Name.

The purpose of the @select function is to allow you to reuse existing code, giving the advantageof having to specify SQL code only once. Specifying SQL only once has two key advantages:• You need to maintain only one instance of the SQL code.


• It ensures consistency of the code.

For example:

This example shows how the @selectworks. The code in the SELECT properties of the Modelobject is:MODEL.MODEL_NAME+' '+ MODEL.MODEL_TRIM+' '+MODEL.MODEL_ENGINE


If you wish to create a new object called Model for Rental with the same code, rather thancreating the same code twice, you can refer to the originalModel object via the @select function:@select(Car\Model)

The benefit is that a dynamic link is created between the objects. When changes occur in theSELECT statement of the original object, the changes are reflected in the SELECT statement ofany other objects that refer to it via the @select function. Therefore, when you change the code,you only change it once in the original object.

@where

The @where function is a pointer to theWhere dialog box properties of another object.

It is used by placing the @where in theWhere field of the Edit Properties dialog box of an object,using the following syntax:@where(path of existing object)

For example:


This example shows how the @whereworks. The code in the Where properties of the Modelfor Rental object is:MODEL.MODEL_DAYRENT IS NOT NULL AND SHOWROOM.SHOWROOM_NAME = @prompt('Enter Showroom Name','A','Showroom\Showroom',mono,constrained)

If you want to create a new object called Showroom Rental Model that has to contain the sameWHERE syntax, rather than creating the same code twice, you can refer to the original Model forRental object via the @where function:@where(Day Rental Charges\Model for Rental)


The benefit is that a dynamic link is created between the objects. When changes occur in theWHERE statement of the original object, the changes are reflected in the WHERE statement of anyother objects that refer to it via the @where function. Therefore, when you need to change thesyntax, you only change it once in the original object.

Note: You can use the @where function in a condition object to point to an object, but not the otherway around.

As with @select, its purpose is to allow you to reuse existing code, and it has the sameadvantages:• You need to maintain only one instance of the SQL code.

• It ensures consistency of the code.

There are further benefits for using the @where function. If there are a number of objects and/orcondition objects that require the same restrictions to be placed upon them, you could use aWHERE restriction object strategy to make the most efficient use of that restriction’s code.


The idea behind the strategy is that you create a new and separate object for every restrictionrequired, in a separate class to the “normal” object classes. Then, within the original objects,whenever a restriction is required, you point to the appropriate WHERE restriction object usingthe @where function.

In the previous example, you can see that twoWhere clause restriction objects have been createdthat contain only a name and Where clause restriction, as follows:

Rental model

MODEL.MODEL_DAYRENT IS NOT NULL

Showroom choice

SHOWROOM.SHOWROOM_NAME = @prompt ('Enter Showroom Name','A','Showroom\Showroom',mono,constrained)

Note that each of the Where clause restriction objects do not have SELECT properties specified.

The @where pointer can now be used to specify the restrictions required for the object calledModel for Rental without the need to double up on the WHERE syntax.

Also, by specifying each restriction in a separate Where clause restriction object, the strategyhas enabled you to build up the multiple restrictions on the object one step at a time. This isparticularly useful when creating complex restrictions on an object.

Moreover, the individual restrictions can be used for other objects and condition objects. In theexample above, theWhere clause restriction object called ShowroomChoice has also been usedfor the Showroom condition object.

For this strategy to work, you need to be able to hide the class containing all the Where clauserestriction objects from end users.

The Where clause restriction object strategy has a number of advantages:• Maintenance is easy because only a single instance of each restriction is required.

• The restrictions are easy to find. They are all under a single class. Restrictions can be mixedand matched without the need for repetition.

To hide the class containing all theWhere clause restriction objectsfrom end users

1. Click the class or object you want to hide.

2. There are different ways to hide classes and objects:• Select the Show or Hide Item button on the Editmenu.• Right-click the object or class and selectHide Item(s) from the drop-down menu.• Use Ctrl+Shift+H.

Hidden classes and objects appear in italics in the DesignerUniverse pane. They are notshown at all in Business Objects end-user querying tools.


@aggregate_aware

Somedatabases contain SummaryTables. These tables are created by theDatabaseAdministrator(DBA) and contain figures such as revenue aggregated to a high level (year, for example) ratherthan to the fact/event level. The summary tables are usually populated and updated regularlyby an automated program that runs SQL against the fact or event data at transaction level.

This means that there are two methods that you can use to return aggregated data:• Run a SELECT statement for the fact or event data

• Run a SELECT statement for the summary data

Where possible, it is best to choose the latter method as the statement will process quicker.

In Designer, you can use a function called @aggregate_aware in the SELECT statement for anobject, so that bothmethods are referenced. This function directs a query to run against aggregatetables whenever possible. If the data in the aggregate table is not calculated at the level ofgranularity required to run the query, the object will direct the query to run against the tablescontaining the non-aggregated data.

A universe that has one or more objects with alternate definitions based on aggregate tables issaid to be aggregate aware. These definitions correspond to levels of aggregation. For example,an object called Profit can be aggregated by month, by quarter, or by year.

The reliability and usefulness of aggregate awareness in a universe depends on the accuracyof the aggregate tables. They must be refreshed at the same time as all fact tables.

When you apply the @aggregate_aware function, be aware of the available levels, and be clearabout the descending order of aggregation.

Each aggregation level SELECT statement is separated by a comma, and the entire expressionis enclosed in brackets. The final SELECT statement must be valid for all queries.@aggregate_aware(<SELECT statement for highest agg level>,<SELECT statement for second highest agg level>, .. <SELECT statement for second lowest agg level>, <original SELECT statement for basic agg calculation>)

Note: Setting up aggregate awareness in a universe is a four-part process. For more information,refer to the BusinessObjects XI Release 2: Designer’s Guide.

Activity: Using @functions

Objective

• Apply @functions to objects and condition objects.

Continue to work with the Model for Rental dimension object that you created in the DayRental Charges subclass. This object returns all models available for rental. This is to be usedby sales staff and requires further restriction to a specific showroom.

Instructions

1. Use the @prompt function to achieve this. The parameters for the @prompt are:


• Prompt = 'Enter showroom name'• Data type = 'A'• LOV = 'Showroom\Showroom'• Mono• Constrained

2. The SELECT properties of the Model and Model for Rental objects are the same. Use the@select in theModel for Rental object to point to the SELECT properties of theModel object.

3. Create a new condition object called Showroom Rental Model in the Showroom class. TheWhere clause restrictions for this condition already exist in theModel for Rental object. Usethe @where function in the condition object to point to the where properties of theModel forRental object.

4. Create a new class called Where Restriction Objects.

5. Create two new objects to go into the Where Restriction Objects Class as follows:• Rental Model containing the restriction:

MODEL.MODEL_DAYRENT IS NOT NULL

• Showroom Choice containing the restriction:SHOWROOM.SHOWROOM_NAME = @prompt('Enter showroom name', 'A', 'Showroom\Showroom', mono, constrained)

6. Hide the Where Restriction Objects Class.

7. Edit the following object and condition object so that the WHERE clause of each contains noSQL code, but instead uses @where functions to point to theWhere clause restriction objects.• Model for Rental object inherits the Rental Model object’s WHERE clause.• Showroom Rental Model condition object inherits the Showroom Choice object’s WHERE

clause.

8. The SELECT properties of the Rental Date andReturnDate objects contain RENTAL.SALE_DATE.Use the @select in the Return Date object to point to the SELECT properties of the RentalDate object to avoid duplication of SQL code.

9. Create a Maker Choice condition object under the Car class that, when used in a query,produces a prompt dialog box requesting the user to enter a single manufacturer.

10.Check the integrity of the universe.

Note: The Integrity Check dialog box alerts you regarding the two hidden objects.


Note: Remember to test your solution in Web Intelligence.


Quiz: Using @functions with objects1. What parameter does the @select require?

2. True or False. You can use the @where function in a condition object to point to an object,but not the other way round.

3. What function is used to create an interactive object that causes amessage to appear at queryruntime, that asks the user for specific input?

a. @where

b. @ prompt

c. @select

d. @aggregate_aware

4. In the @prompt two parameters are mandatory and three are optional. What parameters areoptional?



• Use @functions



Lesson 11Using Hierarchies

Lesson introductionHierarchies allowyou to organize dimension objects so that users canperformmulti-dimensionalanalysis using drill mode in end-user queries.


• Understand hierarchies and universes• Work with hierarchies

235Using Hierarchies—Learner’s Guide

Understanding hierarchies and universesHierarchies in universes allow users to create reports that are enabled for multi-dimensionalanalysis with drill mode.


• Explain how hierarchies allow users to drill down to different levels of detail using drillmode in end-user queries.

Hierarchies

Ahierarchy is an ordered series of related dimension objects that are used formulti-dimensionalanalysis. For example, a geographical hierarchy could group together dimension objects suchas Country, Region and City.

Multi-dimensional analysis is a technique for manipulating data so that it can be viewed fromdifferent perspectives and at different levels of detail. In Business Objects end-user queryingtools, users can analyze data at different levels of detail using a feature known as drill mode.

The example below shows a hierarchy of the dimension objects Country, Region and City.

At the highest level, the user will see a Country. At the next level down, the Country is brokendown into more detail: the regions. At the next lower level, the regions are broken down intomore detail: the cities. A user can then analyze ameasure object, such as Sales Revenue, againstany of the levels in the hierarchy.

Natural hierarchies

A natural hierarchy is one that follows a naturally occurring pattern from the most general atthe highest level to the most detailed at the lowest level. Examples of natural hierarchies canbe found in the geographical definitions of places and in the measurement of time:• Country, Region, State, City, District, Street

• Year, Quarter, Month, Week, Day

Logical hierarchies

BusinessObjects hierarchies are not restricted to natural hierarchies. You can construct ahierarchy from any related group of dimension objects that will create a sensible analysis path.

The relationship between the dimension objects in a hierarchy normally will be one-to-manyas you descend through the levels.


For example, one Country has many Towns; one Town has many Showrooms; one Showroomhas many Franchises.


Working with hierarchiesAfter completing this unit, you will be able to:

• View default hierarchies in a universe• Set the scope of analysis in a Web Intelligence document using a default hierarchy• Create a custom hierarchy• Create time hierarchies

Default hierarchies

Adefault hierarchy contains all the dimension objects in a class in the order they are presentedin that class. It is based on the order of the objects within the class.

As the name suggests, a default hierarchy is automatically inferred by BusinessObjects end-userquerying tools whenever you have at least one dimension object in a class.

It is therefore important to organize dimension objects hierarchically in a class.

In this example, you can see that the dimension objects in each class follow an order from themost general to the most specific.

Using this method of organizing your dimension objects in their classes is the key to settingup usable default hierarchies.


To view the Default Hierarchies

1. There are two methods to view the default hierarchies:• Select Tools ➤ Hierarchies from the menu bar.• Click theHierarchies toolbar button.

This opens theHierarchies Editor dialog box:

You cannot add or remove objects from classes in theHierarchies Editor.

You can use theHierarchies Editor to create Custom Hierarchies.

2. Click the + box next to any class if you want to see the dimension objects organized in thesehierarchies.

3. Click Cancel to close theHierarchies Editor dialog box.

To test a default hierarchy

Aswith other components of a universe, hierarchies can be tested inWeb Intelligence, to checkthat they function as expected.1. In Web Intelligence, create a new document. Select the relevant universe.

2. In the Edit Query view, select an object that is the highest level of one of the hierarchies,and move it into the Result Objects pane.

3. Select a suitable measure object, and double-click it to add it to the Result Objects pane.

4. Click the Show/Hide Scope of Analysis pane button on the Web Intelligence Edit Queryview toolbar.


This opens the Scope of Analysis pane.

The Scope of Analysis pane allows users to set up the query for drill analysis. All thedimensions selected for the query are highlighted here, within their default hierarchies. Inorder to allow users to drill down the hierarchy from one level to another, without havingto modify the query, you can set the scope of analysis before the query is actually executed.

Note: You can manually drag the objects you want to drill down to in this pane. In thiscase, the Custom value appears in the Scope of Analysis level drop-down list.

5. To define default levels of scope of analysis, select the level drop-down list in the Scope ofAnalysis, and click the arrow to select the scope of analysis levels.

The levels you define in the scope of analysis will determine how many objects from thehierarchywill be included in the query, and therefore howmany levels of detailed data willbe returned to the Web Intelligence document.

6. Select the required level from the drop-down list.

The Scope of Analysis pane will contain further dimensions, indicating the level downoption you have just selected.

This means that they will be included in the query, and the measure relevant to these twoobjects will be calculated and stored in the document’s microcube.

7. Click Run Query to execute the query.

Values returned by the two dimension objects will not immediately appear in the table thatis displayed, but can be seen listed in theData tab of the Report Manager on the side.

As soon as a user decides to switch to drill mode, the data will be available for drill analysis.

8. Click theDrill button in the Reporting toolbar to display the report in drill mode.

Note: The report page now shows the name Report 1 with a drill mode icon.


9. Move the mouse pointer over a value in the dimension object column.

A flag appears indicating the next level of data available from the hierarchy.

10.Double-click to drill down. The data in the measure column is aggregated to reflect nextlevel drill-down figures.

11.Drill down and up as you wish to explore the data available in the document’s microcube.

Custom hierarchies

A custom hierarchy combines objects from default hierarchies to build a custom analysis path.

Default hierarchies are based on the order of the dimension objects in their classes. These defaulthierarchies may not provide the drill paths that users need to analyze their data. They mayneed to follow drill paths that contain dimension objects from more than one class.


For example, if users of the Motors universe wanted to look at Sales Revenue from the pointof view of Client/Area and Financial Period, theywould not be able to do this using the defaulthierarchies.

As universe designer, you can build a permanent custom hierarchy as part of the universe. Asa result, the hierarchy is available across documents to all users.

In the analysis phase of the universe development process, the designer identifies those customhierarchies that are to be used regularly and creates them in Designer as permanent customhierarchies.

To create a custom hierarchy

1. There are two methods to create a custom hierarchy:• Select Tools ➤ Hierarchies from the menu bar.• Click theHierarchies toolbar button.

This opens theHierarchies Editor dialog box:

2. ClickNew.

A new folder appears in the Custom Hierarchies pane.

3. Type a name for the custom hierarchy as the folder name, and press Enter.

4. In the left panel of theHierarchies Editordialog box, click the + box of the default hierarchiesthat contain the dimension objects you want to include in the custom hierarchy.

The default hierarchy dimension objects appear.

5. There are several methods to add the dimension objects to the custom hierarchy:• Select the object that you want to appear in the custom hierarchy, and click Add.• Select multiple objects by holding the Ctrl key down, and click Add.• Drag and drop the required objects to the new custom hierarchy folder.

The selected objects appear in the custom hierarchy.

Note: The dimension objects may not be in the order you require. You canmove the objectsup and down the list by clicking them and then clicking theMove Up orMove Downbuttons. Alternately, you can use the drag-and-drop technique.

6. ClickOK to save the changes to the hierarchies and close theHierarchies Editor dialog box.


The effect of custom hierarchies on default hierarchies

In Web Intelligence, if you look at theHierarchiesmode in the Java Report panel before youcreate any Custom Hierarchies, you will see that the list of hierarchies is shown in the sameorder as the objects in the All Objectsmode: both show a full list of default hierarchies.


However, when you create a Custom Hierarchy, theHierarchiesmode lists only the customhierarchies while the All Objectsmode still shows all objects made available to the user.

At first, this appears to be a problem. However, the effect of creating a custom hierarchy isactually very useful because it provides a mechanism for selectively producing hierarchies forend users.

Because a default hierarchy is always created for any class where a dimension object exists, itmay be that there are some default hierarchies that you do not want users to use as drill paths.This mechanism can be used to exclude such default hierarchies.

Once you decide to create custom hierarchies, youmust copy any of the defaults that youwantto keep over to the right-hand side list box. Even if you do not want to create new ones, toexclude the default hierarchies that you do not want users to use as drill paths, you must copythe useful ones over.

In order to make any change at all in the hierarchies, you either start over by creating newcustomhierarchies or you copy only the useful default hierarchies into the CustomHierarchieslist box.

To selectively make default hierarchies available to users

This topic discusses how to add selected default hierarchies to the list of custom hierarchies inDesigner.1. There are two methods to create a custom hierarchy:

• Select Tools ➤ Hierarchies from the menu bar.• Click theHierarchies toolbar button.

This opens theHierarchies Editor dialog box.


2. Drag and drop only the default hierarchy folders you want the users to use as drill pathsfrom the left panel of theHierarchies Editor dialog box to the right panel.

Note: Whenmore than one hierarchy startswith the samedimension object path but divergesat a lower level of the hierarchy, the default path in the user module will be the one that ishigher in the list (if dimensions from both hierarchies are included in the query). You canalter this default priority by changing the order of the hierarchies in theCustomHierarchiespane. You can do this using theMove Up andMove Down buttons, or using thedrag-and-drop technique.

Note: When you add default hierarchies to the Custom Hierarchies list, it is good practiceto position the true custom hierarchy, if any, at the bottom of the list.

3. ClickOK to save the changes to the hierarchies and close theHierarchies Editor dialog box.


Time hierarchies

One of the most common requirements for data analysis is to provide facilities for analysisagainst different time periods.

Time is a special case because all the information for the dimension objects that make up thehierarchy can come from a single column in a database. In most other cases, each dimensionobject infers a separate database column.

This is achieved by using SQLdate scalar functions to extract the day,month, year, and possiblyquarter from a single database column of a date type.

When you create a Time Hierarchy, you are still creating a Default Hierarchy, in which thelevels depend on the order of the Dimension objects. You create the standard time structure


by ordering the objects Year, Quarter, Month, and Week. The only difference with TimeHierarchies is the way in which you create the objects.

Creating time hierarchies

There are three methods of creating a time hierarchy. Each method has advantages anddisadvantages for both the designer and the user. The three methods are:• Automatic time hierarchies

• Using database functions

• Table-based time hierarchies

To create an automatic time hierarchy

Using this method, Designer automatically creates the dimension object definitions needed fora time hierarchy from a single Date Seed object.

Automatic time hierarchies can only be applied to objects with Date type.1. Double-click a date object to open the Edit Properties dialog box.

Note that the Type field is set to Date.

2. Click the Properties tab. With the field type set toDate, the Automatic Time Hierarchybutton is shown in theQualification pane.

3. Click theAutomatic TimeHierarchy button to open theAutomatic TimeHierarchy dialogbox.


4. Select the check boxes for the time-related dimension objects you want to create and editthe names of the dimension objects, if required.

5. ClickOK to close the Automatic Time Hierarchy dialog box.

6. If necessary, alter other object properties as required.

7. ClickOK to close the Edit Properties dialog box.

In the Universe pane, the original date object has a plus next to it, indicating that otherobjects are attached to it. These are the automatically created time dimension objects.

8. Click the + box to view and check the objects attached to the date object.

Note: You can see that the arrangement of the objects is not as youmight expect. The originaldate object is at the top of the hierarchy, and the other time objects appear to be subsidiaryobjects to it. From this, it is apparent that there are two further disadvantages to thismethodof creating time dimension objects. First, when a user sees a + box against an object, theywill think that detail objects are attached to it. Second, the objects are not orderedhierarchically in the class, and, as a consequence, this might lead to confusion as to whichis the highest-level object in the class.

9. Double-click one of the automatically created time dimension objects (year, quarter, ormonth) to view the Edit Properties dialog box for the object.


Note: The object properties cannot be edited. This is another disadvantage. However, youcan also see one of the key advantages of using thismethod to create time dimension objects:the SQL inferred includes the scalar function used to extract the correct element of the date.

10.ClickOK to close the Edit Properties dialog box.

11.Click theHierarchies toolbar button to open theHierarchies Editor dialog box.

Notice that in theDefault Hierarchies list, there are two new default hierarchy classes, anempty one bearing the name of the original class, and another bearing the name of the classappended with the name of the original date object.

12.Click the + box next to the class/object-named default hierarchy.You can see that the time hierarchy objects are correctly ordered despite the order of thedimension objects in the class.

13.Close theHierarchies Editor dialog box.


Testing automatic time hierarchies

Automatic time hierarchies are tested in the same way as any other hierarchy. However, thereis one thing to note about such a test.

When you drill down to the bottom of the time hierarchy, the Quarters and the Months areidentified simply as numbers, 1 to 4 for the Quarters and 1 to 12 for the Months.


This can be confusing or unsatisfactory to end users. A better idea is to precede the numberswith a character string such as Quarter or Month. However, as you have already seen, it isimpossible to edit a time dimension object that is created using the automated method.

Advantages and disadvantages of automatic time hierarchies

This section lists the advantages and disadvantages for using automatic time hierarchies.

Advantages

• It is a fairly quick and easy way to set up a time hierarchy.

• Automatically creates the SQL SELECT statement using the appropriate scalar functions forthe RDBMS of the target database.

Disadvantages

• Does not give the designer any control over the layout of the dimension objects in theUniverse pane.

• Does not give the designer any control over the format of the data in the query report.

• The layout of the dimension objects in the universe can be confusing to users, who normallyexpect to see detail objects under dimension objects.

• The format of the report can be confusing to users.

• An LOV can only be applied to the date seed object, not to individual time dimension objects.

All the negative points listed above can be avoided if anothermethod of creating time dimensionobjects is used.

Time hierarchies based on database functions

You can use the scalar date functions to create time dimension objects manually.

Note: However, the set of scalar functions used to extract elements of a database varies with eachRDBMS.

To create a time hierarchy using database functions

1. Create a new class or subclass with an appropriate name.


Repeat the remainder of this procedure to create each time object required within the classthat is based on the date scalar functions.

2. Drag the database column from the Structure pane table that contains the date requiredand drop it on the newly created class.

3. Double-click the object to open the Edit Properties dialog box.

4. Edit the properties of the object so that it will infer an element of the date as required.• Change the object name to reflect the scalar function used.• Change the Type if required, depending on the scalar function used.• Change the SELECT statement to the relevant scalar function, string conversion, and

required concatenated string value, depending on the RDBMS used.• Clear the Associate list of values, if not required.

5. ClickOK to close the Edit Properties dialog box.

6. Repeat steps 2 to 5 for each of the other time objects requiredwithin the class based on scalarfunctions.

Tip: As you are creating a very similar time object to the previous one, it can be moreefficient to edit a copy of the previous object, rather than creating a new one as suggestedin step 2.

7. The Universe pane now contains a class or subclass as in the following example:

A default time hierarchy will now be inferred from the class.

Note: A time hierarchy created using this method is tested the same way as any other hierarchy.

Advantages and disadvantages of database function timehierarchies

This section lists the advantages and disadvantages for database function time hierarchies.

Advantages

• The layout of the dimension object within the class is as a user would expect.

• Each of the objects can be edited individually.

• A separate LOV can be associated with each time dimension object as required.

• The name of the hierarchy and the order of the objects mirror the class exactly.


Disadvantages

• It takes longer to create the objects of the time hierarchy than when using the AutomaticTime Hierarchy method.

• The person designing the universe needs to know the relevant scalar functions and how touse them.

Tip: If you do not know the relevant scalar functions, you could initially create the time objectswithin a class using the Automatic Time Hierarchy method. Then you could note the scalarfunctions automatically inferred, remove the automatically created objects, and recreate themusing the database function method.

Table-based time hierarchies

The Automatic Time Hierarchy and Database Functions methods of creating a time hierarchyare appropriate when you want to create calendar-based time dimension objects. However,they are inappropriatewhen youwant to create time dimension objects based on different timeperiods.

Another way of creating time dimension objects is to add a time-range table to the databasewith columns and data as in the following example. This table can then be added to the structureand its columns used to create time dimension objects. This is a good way of coping withfinancial periods that do not coincide with the calendar year.

To create a table-based time hierarchy

1. Add the time period table to the universe structure.

2. Insert a theta join between the start and end range columns of the time period table and anappropriate date column of another table.

An example of this is shown below:


3. Create a new class with an appropriate name.

4. Create the time objects required. In each instance, you will not need to use scalar functions.The SELECT statement of each object needs only to infer a database column name. Hence, itwould be more efficient to use the automated method of creating objects (drag and drop).

When the objects have been created, the class appears as in the example below:

A default time hierarchy will now be inferred from the class.


Note: A time hierarchy created using this method is tested in the same way as any other hierarchy.

Advantages and disadvantages of table-based time hierarchies

This section lists the advantages and disadvantages of table-based time hierarchies .

Advantages

• It is a good method of creating time dimension objects for time periods other than calendarperiods.

• The layout of the dimensions within the class is as a user would expect.

• Each of the objects can be edited individually.

• A separate LOV can be associated with each time dimension object, as required.

• The name of the hierarchy and the order of objects mirror the class exactly.

Disadvantages

• The additional join reduces the efficiency of an inferred SQL statement.


Activity: Using hierarchies

Objective

• Infer default hierarchies and create custom hierarchies for the Motors universe.

Note: Switch back to default hierarchies if you have followed along during this lesson.

Instructions

1. To view all hierarchies, click the hierarchy button. Remove all custom hierarchies in theCustom section.

2. Check that the hierarchical order of the dimension objects in the Client class is based ongeography.The geographic hierarchy is: Country -> Region -> Area -> Town.

3. Save and export the universe, and then test the default hierarchy in Web Intelligence.

4. Create a Sale Year, Sale Quarter, and Sale Month dimension object using the AutomaticTime Hierarchy method.

5. Save and export the universe again, and then test the resulting hierarchy inWeb Intelligence.When you run the query, view the SQL and note the scalar function used.

6. Create a Rental Year, Rental Quarter, and Rental Month dimension object manually in theRental Dates subclass.Ensure that the quarter and month dimension object values are formatted to show a fullmonth value or are preceded by a character string such asQ andCalendar Year respectively.

7. Check that the order of the dimension objects in the Financial Period class is based on time.

8. Save and export the universe again, and then test the resulting hierarchies inWeb Intelligence.

9. Prestige Motors wants to analyze clients geographically (by Country, Region, and Town)but then further analyze the breakdown of client expenditure by financial year.Create a custom hierarchy to allow users to do this by including the Country, Region, Townand Financial Year objects in the hierarchy.

10.Make the following default hierarchies available to the user:• Car• Day Rental Charges• Showroom• Financial Period• Rental Dates• Sale Dates

11.Save and export the universe again, and then test the resulting hierarchy inWeb Intelligence.

12.Sales people want to drill down to a model using a specific drill path. In the bottom of yourcustom hierarchy list, create a hierarchy to allow this drill path using the following objects:• Showroom Country


• Showroom Name• Maker• Model

13.Save and export the universe again, and then test the resulting hierarchy inWeb Intelligence.


Quiz: Using hierarchies1. Select the hierarchy that is based on the order of the objects within the class.

a. Custom

b. Default

c. Chronological

2. What are two advantages of Automatic Time Hierarchies?



• Understand hierarchies and universes• Work with hierarchies



Lesson 12Derived Tables and Indexes

Lesson introductionA derived table is a dynamic, virtual table that you create within the universe structure. Itallows you to transfer more of the processing load from the report server to the database andimprove query execution performance.

Index awareness is the ability to take advantage of the database indexes on key columns tospeed data retrieval. The objects that you create in the universe are based on database columnsthat are meaningful to an end user.


• Use derived tables• Apply index awareness

257Derived Tables and Indexes—Learner’s Guide

Using derived tablesThis unit explains what derived tables are and how you create them as dynamic, virtual tablesin the universe.


• Understand the advantage of adding derived tables to your universe structure• Insert a derived table in the universe

What is a derived table?

A derived table is a dynamic, virtual table that you create within the universe structure. Itconsists of a set of SQL statements that you create in Designer, and that you can then use as alogical table to create objects.

In the derived table’s SQL set, you can put a SELECT statement in place of a table name in theFROM clause. The SQL set can also contain embeddedprompts, and you can create joins betweenthe virtual derived table and the physical tables, just as you can with other tables.

Derived tables are similar to views in the database, but as they are defined in the universe, theygive universe designers more flexibility. You can see a derived table as a query that can bereferenced as a table. The table definition SQL is inserted into an end-user query at run time.

Note: As it is a query and not a physical table, it is important to understand that the sameperformance issues that can affect queries can also affect derived tables.

Derived tables can be used tomerge data together fromdifferent tables,whenuniverse designersare unable to conform the underlying data source, and want to normalize or denormalize theuniverse schema.

Adding derived tables

Derived tables appear in your Designer schema in exactly the same way as normal databasetables, but the workflow for creating them is different.

To create a derived table

1. Select Insert ➤ Derived Tables.

TheDerived Tables dialog box displays.

2. Type the table name in the Table Name dialog box.

3. Build the table SQL in the box beneath the Table Name box.You can type the SQL directly or use the Tables and Columns, Operators and Functionsboxes to build it.


Note: When using an aggregation function, or any other SQL function in the SQL syntax,it is important to alias the column that contains the calculation. Universe Designer usesthese aliases as the column names in the derived table.

4. Click Check Syntax to parse and validate your SQL.

5. ClickOK.The derived table appears in the schema next to the physical database tables.

6. Join the table to a table in the existing schema.If contexts have been applied to the schema, make sure the newly inserted join is includedin at least one context.

7. Build objects based on the derived table columns in exactly the same way you do withregular tables.


To edit a derived table

1. Right-click the table in theDesigner schema and selectEditDerived Table from the shortcutmenu.

2. Edit the derived table, and then clickOK.


Derived tables as lookup for multiple contexts

Derived tables can be useful to combine data from two separate fact tables. If fact tables arespread across two separate contexts, combining measures from each of these tables will resultin separate SQL statements.

In theMotors schema there is a context for Sales and a context for Rentals. End users maywishto see Clients with both Rental Total and Sales Total data.

You can combine the data in a derived table and by basing the Sales and Rental total objectson the new derived table will avoid users having to select measures from multiple contexts.


Activity: Adding derived tables

Objective

• Create a derived table that shows the number of transactions per customer.

Instructions

1. Using Motors, insert a derived table to show the number of transactions per customer.

2. Name the newly derived table Best_Cust.

3. Create the SQL statement so that it looks like this:SELECT CLIENT.CLIENT_ID, COUNT(SALE.SALE_ID) AS Number_of_transactionsFROM CLIENT, SALEWHERE CLIENT.CLIENT_ID=SALE.CLIENT_IDGROUP BY CLIENT.CLIENT_ID

4. Use Check Syntax to verify your SQL statement syntax.

5. Insert a join between the Best_Cust and Client tables.

6. Add the new join to the Sales context.The join between the Best_Cust and Client tables is from the Client_ID primary key in theClient table to the Client_ID foreign key in the Best_Cust table.The table schema looks like this.

7. Add the Number of Transactions object to the Client class. Define the object as a measureobject.


9. InWeb Intelligence, build a report that shows the number of transactions per customer andthe number of transactions per country.


Applying index awarenessThis unit describes how to set up a universe in Designer to take advantage of primary andforeign keys that may already exist in the data source.


• Understand what index awareness is• Set up primary key index awareness• Set up foreign key index awareness

What is index awareness?

Index awareness is the ability to take advantage of the indexes on key columns to speed dataretrieval.

The objects that you create in the universe are based on database columns that are meaningfulto an end user. For example, a Customer object retrieves the field that contains the customername. In this situation the customer table typically has a primary key (for example, an integer)that is not meaningful to the end user, but which is very important for database performance.When you set up index awareness in Designer, you tell Designer which database columns areprimary and foreign keys. This can have a dramatic effect on query performance in the followingways:• Designer can take advantage of the indexes on key columns to speed data retrieval.

• Designer can generate SQL that filters in themost efficientway. This is particularly importantin a star schema database. If you build a query that involves filtering on a value in adimension table, Designer can apply the filter directly on the fact table by using the dimensiontable foreign key. This eliminates unnecessary and costly joins to dimension tables.

Designer does not ignore duplicates with index awareness. If two customers have the samename, Designer retrieves only one unless it is aware that each customer has a separate primarykey.

Setting up index awareness

Report designers in your organization want to build a report using the Motors universe thatreturns the Highest Priced Value retail price by maker, manufactured in the United Kingdomor the United States.

To build this report in Web Intelligence, you would drag the Maker and Highest Priced Valueobjects into theResult Objects pane in theReport Panel. Then, drag theMaker Country objectinto theQuery Filters pane and restrict the countries to the United Kingdom and the UnitedStates.

Without index awareness, Designer generates the following SQL:SELECTMAKER.MAKER_NAME,max(MODEL.MODEL_PRICE)FROM


MAKER,MODEL,COUNTRY COUNTRY_MAKERWHERE (MODEL.MAKER_ID=MAKER.MAKER_ID)AND (MAKER.COUNTRY_ID=COUNTRY_MAKER.COUNTRY_ID)AND COUNTRY_MAKER.COUNTRY_NAME In ( 'United Kingdom','USA' )GROUP BYMAKER.MAKER_NAME

In this case, Designer has created a join to the Maker Country table in order to restrict thecountries retrieved.

With index awareness, you can tell Designer that Country_ID is the primary key of theCountry_Maker table and that it also appears in the Maker table as a foreign key. Using thisinformation, Designer can restrict the countries without joining to the Country_Maker table.

In this case, Designer is able to generate SQL that restricts the countries by filtering the valuesof the Country_ID foreign key.

After setting up Index Awareness for Maker Country, Designer generates the following SQL,where “44” is the United Kingdom Country_ID value and “1” is the USA Country_ID value:SELECTMAKER.MAKER_NAME,max(MODEL.MODEL_PRICE)FROMMAKER,MODELWHERE (MODEL.MAKER_ID=MAKER.MAKER_ID)AND MAKER.COUNTRY_ID In ( 44,1 )GROUP BYMAKER.MAKER_NAME

To set up primary key index awareness

1. There are two ways to set up primary key index awareness:• Right-click the object on which you want to set up index awareness and selectObject

Properties from the shortcut menu.• Select the object and clickObject Properties on the Edit menu.

The Edit Properties Of dialog box displays.

2. Click the Keys tab.


3. Click Insert.

A key line is inserted in the list of keys box.

4. To define key awareness for the primary key:• Click the drop-down arrow next to Primary Key and select Primary in the Key Type list.

• Clickwithin the line under Select field, and then click the ... button that appears, to openthe SQL editing dialog box.

• The Edit Select Statement dialog box appears.• In the Edit Select Statement dialog box, use the SQL Editor to build the primary key

SQL Select clause or type it directly.

5. Select Enable.

6. ClickOK.

7. Repeat steps 3 and 4 for all columns that make up the primary key.

What happens behind the scenes?

By applying index awareness for the Maker Country, by identifying the primary key to use,Business Objects is prompted to add an alternative piece of SQL in the WHERE clause whenevera query uses Maker Country as a condition.


Instead of using the County_Name field fromCountry_Maker table, it will nowuse Country_Idfield from the Country_Maker table. This is determined from the key entriesmade in the objectproperties.

But how did Business Objects convert the Maker Country names selected in the LOV into theprimary key values necessary for the SQL?

The default SQL query that is generated to retrieve the Maker Country LOV is:

SELECT DISTINCTCOUNTRY_MAKER.COUNTRY_NAMEFROMMAKER,COUNTRY COUNTRY_MAKERWHERE(MAKER.COUNTRY_ID=COUNTRY_MAKER.COUNTRY_ID)

Note: The WHERE clause shown here is a result from using the Tables button, and adding theMakertable, to make sure that Maker Country object only returns countries in which car manufacturersexist.

In order to convert theMaker Country names to primary keys, the primary key thatwas definedin the Keys tab is added to the query:

SELECT DISTINCTCOUNTRY_MAKER.COUNTRY_NAMECOUNTRY_MAKER.COUNTRY_IDFROMMAKER,COUNTRY COUNTRY_MAKERWHERE(MAKER.COUNTRY_ID=COUNTRY_MAKER.COUNTRY_ID)

This way Business Objects matches the country names from the Country_Maker table to theprimary key values.

Note: This SQL is visible by either editing the LOV for theMaker Country object and/or tracingSQL that passes through the middleware to the database.

With index awareness defined, if you select Maker Country names from the LOV dialog youindirectly select the primary key values as well. The primary key values acts like a hiddencolumn in the LOV dialog. The operand ‘Value(s) from list’ dialog box in the BusinessObjectsend-user querying tools returns the primary key values that match the visible values in theLOV dialog.

Index Awareness allows universe designers to automatically redirect a WHERE clause conditionto another column that is known to provide better performance at query time. The indexawareness option can be used to determine which column to choose as an alternative basedon database schema knowledge and the RDBMS optimizer.

The LOV values that end users select actually tell Business Objects what primary key valuesto substitute in final query SQL. The Keys tab tells Business Objects which SQL syntax tosubstitute in the final query SQL.

To view the altered LOV

1. Double-click the indexed object to access theObject Properties.



3. Click Edit.

TheDesignerQuery Panel opens displaying the indexed object in theResult Objects pane.

4. Click View SQL.The SQL Viewer Opens.

It now displays both the indexed object value and its index key as generated columns in theLOV.

Avoiding joins in tables

Another use of index awareness is to reduce the number of tables or joins involved in a query.Reducing the number of joins in a query can help improve query performance.

The SQL from the last example improved performance by restricting on the primary key(indexed) of the Country_Maker table.

SELECTMAKER.MAKER_NAME,max(MODEL.MODEL_PRICE)FROMMAKER,MODEL,COUNTRY COUNTRY_MAKERWHERE (MODEL.MAKER_ID=MAKER.MAKER_ID)AND (MAKER.COUNTRY_ID=COUNTRY_MAKER.COUNTRY_ID)AND COUNTRY_MAKER.COUNTRY_ID In ( 44,1 )GROUP BYMAKER.MAKER_NAME

This query has the Maker and Country_Maker tables in it which both can provide theCountry_ID column.

The Country_Maker table is only needed to satisfy the WHERE clause and is not needed in theSELECT or GROUP BY clauses.

Using Index Awareness it is possible to remove the Country_Maker table from the querycompletely, by telling BusinessObjects to use theMaker table to retrieve Country_ID data from.

By defining the foreign key in the Maker Country object, the same query returns the followingSQL:

SELECTMAKER.MAKER_NAME,max(MODEL.MODEL_PRICE)FROMMAKER,MODELWHERE (MODEL.MAKER_ID=MAKER.MAKER_ID)AND MAKER.COUNTRY_ID In ( 44,1 )GROUP BYMAKER.MAKER_NAME

The Country_Maker table is no longer referenced in the SQL. This table no longer shows upin the FROM clause, nor in the WHERE clause as a join to the Maker table or as a table used toretrieve the condition values from.


Note: The LOV SQL is only affected by the primary key entry and always returns the primarykey entries ‘behind the scenes’. Therefore all columns you provide in foreign key entries musthave the same type of values and column type as the column referenced by the primary keyentry.

To set up foreign key index awareness

1. Right-click the object on which you are setting up index awareness and selectObjectProperties from the shortcut menu.

The Edit Properties dialog box displays.

2. Click the Keys tab.

3. Click Insert.

A key line is inserted in the list of keys box.

4. To define key awareness for the foreign key:• Select Foreign in the Key Type list.• Click in the Select field and then click the ... button.• In the Edit Select Statement dialog box, use the SQL Editor to build the foreign key SQL

SELECT or type it directly.

5. Repeat steps 3 and 4 for all columns that make up the primary key.

6. Select Enable.

7. Repeat the steps for all columns in the foreign key and then clickOK.

Multiple foreign key entries

The Keys tab allows more than one foreign key entry. This allows you to deal with repeatedvalues in multiple tables (denormalized data).

Database designers may denormalize primary key values beyond what is necessary to satisfyconstraints or to assist in performance and simplification of SQL generation.

It is expected to see an entity repeated twice: initially in the entity’s own table as its primarykey and then in a table that refers to this primary key through its foreign key.

Denormalization implies that the database designer has gone beyond this duplication and hasmore than two instances of the value in a schema.

In the Motors schema you can find such a scenario with the following tables:• Client• Region• Country_Region

All three tables contain a Country_ID column.


If you set up the keys for the Client Country object we can give Business Objects three choicesfrom which it can retrieve these values for the purposes of restricting data in the WHERE clause.This can aid query performance.

When running the Web Intelligence query shown above, the SQL generated is as follows:SELECTCLIENT.CLIENT_LASTNAME + ', ' + CLIENT.CLIENT_FIRSTNAME,REGION.REGION_NAMEFROMCLIENT,REGIONWHERE(REGION.COUNTRY_ID=CLIENT.COUNTRY_ID)ANDREGION.COUNTRY_ID In (1,44)

The Region table is used to restrict on Country_Region (Country_ID) as it is one of the foreignkey entries and the Country_Region table is not used anywhere else in the query and issubsequently dropped from the SQL.

Why does Business Objects use the Region table and not the Client table? Both tables exist inthe FROM clause, however the Region table is used as the Country_ID key replacement.

The reason for this is the order in which the foreign keys have been defined.). The Country_IDkey from the Region table was the last one defined in the list and this is the one that will beused in the SQL generation.

Rearranging the keys by placing the Country_ID key from the Client table last results in thefollowing SQL instead:

SELECTCLIENT.CLIENT_LASTNAME + ', ' + CLIENT.CLIENT_FIRSTNAME,REGION.REGION_NAMEFROMCLIENT,REGIONWHERE(REGION.COUNTRY_ID=CLIENT.COUNTRY_ID)ANDCLIENT.COUNTRY_ID In (1,44)


Note: If a shortcut join has been defined between the Country_Region and Client table, thisshortcut key takes precedence as the foreign key, even if the last foreign key defined is theRegion key.

SQL Editor dialog box

The SQL editor available to the management of Index Aware is the same SQL editor dialogavailable to predefined conditions, objects SELECT and objects WHERE clauses.

If your target database allows them, you can add SQL comments to the PrimaryKey and ForeignKey entries so that they are identifiable in the final query SQL for example: /* IndexAwarenessForeign Key */

To add a string value in the SQL Editor dialog box

1. Edit the object that has been made index aware, and click the Keys tab.

2. Double-click on the primary key select statement and append an appropriate string value.

String values need to be appended by "/*" and closed with "*/"

3. Double-click on the foreign key select statement and append an appropriate string value.

String values need to be appended by "/*" and closed with "*/"

4. ClickOK to apply your changes.

Using an index awareness WHERE clause

In this section you will look at using a WHERE clause for the primary and foreign key. Using aWHERE clause condition in either the primary or foreign key index will act as a data restriction.This may be useful if there is a large amount of data returned for a particular object.

To add an index awareness WHERE clause

1. Double-click the object on which you are setting up index awareness and select the Keystab.

2. Double-click on the primary keyWhere clause field.

3. Type in the required Where clause syntax.

4. Double-click on the foreign keyWhere clause field.

5. Type in the required Where clause syntax.

6. ClickOK to apply the changes.


Activity: Setting up index awareness

Objective

• Apply index awareness to improve the performance of SQL generation inWeb Intelligence.

Instructions

1. Using the Client Country object in Motors, enter the following under Keys:

COUNTRY_REGION.COUNTRY_IDPrimary key

COUNTRY_REGION.COUNTRY_ID=CLIENT.COUNTRY_IDWHERE

CLIENT.COUNTRY_IDForeign key


3. Create a query in Web Intelligence with Client Country and Client Name.

4. Apply a query filter, and use the Value(s) from list option to restrict the data to a singlecountry, such as the United States.

5. View the SQL.Notice that the WHERE clause no longer uses theCOUNTRY_REGION.COUNTRY_NAME=USA statement (or whichever country youspecified). It uses CLIENT.COUNTRY_ID =1.


Quiz: Derived tables and indexes1. What part of the SQL expression does Designer use to create column names in the derived

table?

2. When you insert a derived table and insert joins, what happens if you do not add the newjoin to the appropriate context?

3. How do you apply index awareness on a universe object?

4. How can index awareness improve query performance?



• Use derived tables• Apply index awareness



Lesson 13End-of-Course Challenge

Lesson introductionIn this workshop you will edit and expand the Motors universe so that:

PrestigeMotorsmanagement and personnel can run reports on number of employees, absencesand salaries by country, showroom department, job type, date and employee. Salaries shouldalso be able to be reported on by financial year, quarter, month and date.

Designing a universe is not just about using the Designer module. Careful planning needs totake place before you as a designer even think about starting up the Designer module. Whileworking through the challenge, youwill need to consider each of the five stages in theUniverseDevelopment Cycle process:

Preparation

Examine the database schema, maybe breaking it down into areas which cover particulardepartments to identify which tables will need to be used to satisfy the HR department'srequirements.

Analysis

You require a detailed analysis of the precise information required by the users in each of thedepartments. There are a number of reports that have been identified. The focus must be onthe business language users use to describe the information they require. This can then be usedin the universe design.

Implementation phase 1: Schema Design

The information from the data analysis and user requirements must then be amalgamated tocreate the conceptual design of the universe, its objects and other components. Special notemust be made of any potential issues that might occur based on the design. At this stage, itwould be good to have those identified.

Implementation phase 2: Building the universe in Designer

TheUniverse is created using the tools in the Designermodule. As each part is created it shouldbe tested using the user module. When the universe is correct from a technical and user pointof view it can be distributed to the users.

Maintenance

When a universe has been distributed to the users, the designer is responsible for updatingand maintaining the universe. This means keeping the universe up to date with any changesin user information requirements.


• Design and create the Prestige Motors universe

273End-of-Course Challenge—Learner’s Guide

End-of-course challengeA customer has called you in to provide a Proof of Concept using a sample of their data toensure they are purchasing the correct product. Taking into account the complete product lineof BusinessObjects products, you need to identify which tools would be best for the customer,not necessarily just the ones used in this challenge, but you do not need to go into any greatdetail on additional products.

Your task is to work in a group and discuss the findings of some initial analysis with the HRdepartment of Prestige Motors.

• Breakout session where as a group you need to identify the requirements• Design the initial schema on paper• Present the schema to the rest of the class• Create the universe in Designer• Test your universe in Web Intelligence

Customer scenario

Prestige motors has a total of 260 employees. Of the 260 employees, there are 12 who workwithin HR, few of whom are required to create the reports, most have viewing rights only.Most of the staff can schedule reports. The management needs to see high level reports, andnot just straightforward tables. Showroom staff may be required to generate reports.• Reports to detail the following:

Salary comparison.1.

2. Absence by department.

3. Salary levels versus Absence correlation.

4. Employee listing by manager.

5. List of Absences with Absentee.

6. Hierarchical reporting to be based on time, department and geographic locations.

7. A summary of the number of employees by grade and total salary amount per showroomfor each year.

8. A Salary Cost Report broken down by financial year and country on which you can drilldown to showroom from country and quarter and month from year.

9. A list of absences detailing the employee, job title, showroom, date of absence, durationof absence and reason for absence. These should be arranged by the reason for absence.

10.A summary of the salary costs and absences per showroom and per year.

11.Employees by department and when they were hired.

12.Departmental employee list by manager.

• Sample of objects to provide the above:○ Employee:


Country1.

2. Showroom

3. Department

4. Job Title

5. Distinct Number of employees

6. Manager detail object produces a list of line managers only when reported on andlists all managers from that table.

7. Ensure the country object produces a list of countries the showrooms are in.

○ Salary:Salary Description.1.

2. Financial Year (for Salary and Absence analysis only).

3. Financial Quarter (for Salary and Absence analysis only).

4. Financial Month (for Salary and Absence analysis only).

5. Date of Payment - no LOV, formatted to dd/mm/yyyy.

6. Salary Cost (based on the SALARIES table) - formatted as currency.

○ Absence:Start of Absence - no LOV, formatted to dd/mm/yyyy.1.

2. Duration of Absence (including weekends).

3. Reason for Absence.

4. Absence days - formatted with no decimal places.

Two custom hierarchies are required: one for geographic drilling, the other for time based ona financial year.

Items to watch out for:1. Multipurpose lookup tables.

2. Chasm and fan traps.

3. Additional business requirements.

Activity: End-of-course challenge - Part 1

Objectives

• Conduct a breakout session where as a group you need to identify the requirements.• Design the schema on paper.• Present the schema to the rest of the class.


Instructions

1. Conduct a breakout session where as a group you need to identify the following points:• Strategy: Define the scope of the universe. Identify and review the production and

development architectures. Assemble project teams and define the initial task plan.• Analysis: Identify the ad hoc data access requirements of the user community and record

them in the form of candidate classes and objects. Identify security requirements.• Schema Design: Map objects to corporate data sources. Resolve any circular paths or

loops within the data structures that support the required objects. Plan the architecturefor the project.

• Plan the development environment: Identify resources required to support a developmentuniverse area. Identify source for development data. Verify appropriate connectivity andinitiate any changes or purchases required and plan their implementation.

• Plan the production environment: Identify resources required for a production universe.Locate source of production data. Verify connectivity. Initiate any changes or purchasesrequired and plan their implementation.

• Adopt universe standards: Have appropriate naming conventions for universe names,object definition guidelines, names for simple, complex and aggregate objects, classnames, alias tables, and help text. You may want to incorporate the class name in theobject's name. This may make object names a little long, but it makes it easier for endusers to understand where existing objects in a query come from, especially in reportscontaining many objects, some of which may have similar names. The object's nameshould always precede the class name(s). Example: Rental Date - Rental Dates - Rentals.

• Connectivity and configuration: Ensure the infrastructure is in place to supportconnectivity between users/developers and the enterprise system, including appropriatemiddleware to support the communication between clients and servers. Identify plannedconfiguration for client software. Ensure appropriate resources are available.

• Security and support: Initiate a first look at security requirements - to be refined duringsubsequent phases. Develop a support policy that will be followed when the universegoes into production. Identify necessary resources.

• Changemanagement and training: Identify procedures for the request, review, approvaland implementation of changes to the production universe. It is essential to educate evenexisting users on how to use the universe to meet the business needs.

• Identify the best practices to be followed.• Quality Assurance.

2. You need to identify the following for a high-level presentation:• Have a schema of the universe prepared on paper.• Key points to setting up your deployment:

○ Best practices○ Strategies to adopt○ Design workflow to follow○ Architecture and health checks○ Potential products to use○ Schema of the universe based on the customer scenario


○ Analyze recipients to determine which reporting tool to be used

Activity: End-of-course challenge - Part 2

Objectives

• Create the universe in Designer.• Test your universe in Web Intelligence.

Instructions

1. Create a new universe called HR_Motors.unv.

2. Using your paper design as a reference, design the universe schema. Insert tables, joins, andcreate the appropriate classes and object.

3. Resolve any potential loops or SQL traps.

4. Check the universe integrity.

5. Test the universe in Web Intelligence.



• Design and create the Prestige Motors universe


Appendix ARelational/Dimensional Modeling

Understanding the metadataBefore developing a universe you must familiarize yourself with the underlying data. Whichtype of database schema is going to be used for the universe? Will this be a Data Warehousemodel, an Online Transactional Processing system (OLTP), or a Data Mart? How can you bestimplement the metadata into a universe schema to meet the end user requirements?

279Relational/Dimensional Modeling—Learner’s Guide

Data warehousesA data warehouse is an enterprise wide centralized storage facility for different types of data.Data stored in a datawarehouse is characteristically subject oriented, time sensitive, and shouldbe organized in a way that allows data analysis. For example, a data warehouse can containcustomer information and sales details per customer, over the past five years. These customerdetails and sales records are often derived from several production systems in the enterprise.Performing query and trend analysis on this dispersed data can prove to be a difficult task.

This is where datawarehousing comes into play. Datawarehousing is the process of collecting,aggregating, storing, and maintaining information so that it may lead to accurate businessdecisions. Some characteristics and features of data warehousing are as follows:• Provides a consolidated storage of information from across the enterprise.• Warehoused data is organized by subject area and is populated from many operational

systems.• Can act as a decision support system.• Generally concerned with historical data and aggregates.• Added to regularly, but loaded data is rarely ever directly changed.• Regular schedule of dumps and loads from operational data stores.

All these features differentiate data warehouses from typical operational database systems.Data warehouses are commonly kept on separate machines that can be tuned for a lowerfrequency of userswith different querying characteristics.Datawarehouses are usually read-onlybased systems, aside from the periodic loading of current information.


Online Transactional Processing systemsOperational database systems dealwith handlingmany users and transactions. These databasesare often referred to as Online Transactional Processing systems (or OLTP). These operationaldatabases are continuously used systems in which users add, update, and query the storedinformation.

An example of an OLTP is a typical order-entry application. A customer calls a call center andorders products from a catalog. The sales representative answering the call can pull up theorder entry screen and enter the line items the customer desires. Whenever an order is placedit triggers inventory allocations. This seems like a relatively small process, but it will havegeneratedmany records, andmany underlying transactions. This type ofOLTP system requirestransactions to be speedy and inventory levels to be accurate. The sheer volume of these diverseoperations and the amount of data that is produced provide a poor environment for decisionsupport.

OLTP systems have been designed to support the primary business processes and are optimizedfor transaction processing. To avoid data redundancy and possible data conflicts the datamodelhas been normalized. An OLTP environment is not necessarily designed for querying andreporting,which can potentiallymake universe design based on anOLTP a bitmore challenging.


Data MartsA data mart is a repository of data gathered from operational data or other sources and isdesigned to serve a particular department or functional group. It is similar to aDatawarehouse,but there would be a difference in size and focus. The emphasis of a data mart is on meetingthe specific demands of a particular group of users. These users can run reports and analyzedata stored in the data mart that is designed to portray information based on their grouprequirement needs.

A common approach to using data marts is to keep data at a detail level in the data warehouseand summarize this information into the data mart for each functional group or department.

Sometimes data marts are designed for each departmental unit, and all departmental datamarts are merged later on into an enterprise-level data warehouse.

Either method offers the benefit of centralizing the information for the end users. Somecharacteristics of data marts are as follows:• Data specialized for a particular group of an organization.• Engineered for easy access.• Optimal response from lower volume queries.

Due to more simplified and specialized nature of data marts, organizations are turning to datamarts, as a quick solution to their decision-support needs.


Dimensional ModelingThe traditional entity relationship (ER) model uses a normalized approach to database design.Normalization removes redundancy from the schema to optimize storage. Data warehousingis not that concernedwith saving space. It is more concernedwithmeeting the decision supportneeds. A small amount of redundancy is usually acceptable.

Star and snowflake schemas

Dimensional modeling is a more appropriate approach to the warehouse design. Withdimensional modeling you separate the business data into logical events or facts and a set ofcorresponding dimensions.

This results in a schema that is commonly referred to as the star schema. This schema willnormally contain a large and centralized fact tablewhich branches off intomany small dimensiontables, resembling a star-like layout.

Fact Tables

The fact table that sits in the center of this star schema usually contains business events recordedover time. Examples of data that can be found in this table are: sales transactions, orders andreturns, bank transactions, shipments, and so forth.

The fact table normally consists of a set of numeric values and a number of foreign keys thatcorrespond to primary keys in the various dimension (lookup) tables. The information storedin the fact tables is usually static as it is historical. The most common example of a fact table inthe star schema is for sales.

Dimensions

The dimension tables consist mainly of descriptive information linked to fact records. Exampleof dimensiondata are: customer names, product descriptions, suppliers, andvendors.Dimensiontables contain fewer records than the facts table. An important factor is that the information indimension tables is not static as records in dimension tables can be updated. For example, acustomer address might be modified in the source system.


A typical data warehouse schema will always use dimension tables or tables that deal withperiods of time. These tables are the key element to tracking the time variant information inthese types of databases.

Sometimes a more normalized approach is taken to the dimension tables. When this happensthe star schema changes to a snowflake (or constellation) schema. A snowflake schema isbasically one fact table, connected to a number of dimension tables, and these dimension tablesin turn are connected to additional dimension tables.

In a snowflake schema it is also common to include aggregations across dimensional hierarchies,for example sales values summed up by store. These sales values can also be summarized intoseparate fact tables by region or district.

The dimensional model is a logical technique optimized for queries and reporting. It is themost common model used in current data warehousing or data mart designs. It providessimplified hierarchical paths that would enable end userswith drill-down analysis capabilities.Precalculated aggregations can be also embedded in the fact tables, which can result in rapidquery-response times.


Appendix BAlternative SQL syntaxes for other RDBMS

SQL syntaxes for other RDBMSThis appendix provides the alternative SQL syntaxes for Oracle, MySQL, DB2 and MicrosoftAccess, for the more complex objects used within this course.

285Alternative SQL syntaxes for other RDBMS—Learner’s Guide

DB2MySQLOracleObjectName

{fn concat({fn concat(CLIENT.CLIENT_LASTNAME,',

{fn concat({fn concat(CLIENT.CLIENT_LASTNAME,',

CONCAT(CONCAT(CLIENT.CLIENT_LASTNAME,',Client

Name ')},CLIENT.CLIENT_FIRSTNAME)}

')},CLIENT.CLIENT_FIRSTNAME)}

'),CLIENT.CLIENT_FIRSTNAME)

{fn concat({fn concat({fn concat({fn concat(

{fn concat({fn concat({fn concat({fn concat(

CONCAT(CONCAT(CONCAT(CONCAT(MODEL.MODEL_NAME,'

ModelMODEL.MODEL_NAME,' ')}MODEL.MODEL_NAME,' ')}

'),,MODEL.MODEL_TRIM)},' ,MODEL.MODEL_TRIM)},'

MODEL.MODEL_TRIM),' '),MODEL.MODEL_ENGINE)

')},MODEL.MODEL_ENGINE)}

')},MODEL.MODEL_ENGINE)}

{fn concat('Calendar Year

{fn concat('Calendar Year ',YEAR(SALE.SALE_DATE))}

CONCAT('Calendar Year ',TO_CHAR(SALE.SALE_DATE,'YYYY'))

SaleYear ',char(year(

SALE.SALE_DATE)))}

{fn concat('Q',char(quarter(SALE.SALE_DATE)))}

{fn concat('Q',QUARTER(SALE.SALE_DATE))}

CONCAT('Q',TO_CHAR(SALE.SALE_DATE,'Q'))

SaleQuarter

MONTH(SALE.SALE_DATE)MONTH(SALE.SALE_DATE)TO_CHAR(SALE.SALE_DATE,'Month')

SaleMonth

{fn concat('Calendar Year

{fn concat('Calendar Year ',YEAR(RENTAL.SALE_DATE))}

CONCAT('Calendar Year ',TO_CHAR(RENTAL.SALE_DATE,'YYYY'))

RentalYear ',char(year(

RENTAL.SALE_DATE)))}

{fn concat('Q',char(quarter(RENTAL.SALE_DATE)))}

{fn concat('Q',QUARTER(RENTAL.SALE_DATE))}

CONCAT('Q',TO_CHAR(RENTAL.SALE_DATE,'Q'))

RentalQuarter

MONTH(RENTAL.SALE_DATE)MONTH(RENTAL.SALE_DATE)TO_CHAR(RENTAL.SALE_DATE,'Month')

RentalMonth

sum(CASE WHEN year(SALE.SALE_DATE) =

sum( CASE WHEN {fn year(

sum(CASE WHEN to_char(SALE.SALE_DATE,'YYYY')

SalesRevenue2003

2003 THEN

SALE.SALE_DATE )} = 2003

='2003' THEN (SALE_MODEL.SALE_QTY

(SALE_MODEL.SALE_QTY *THEN (SALE_MODEL.SALE_QTY ** MODEL.MODEL_PRICE *(100

MODEL.MODEL_PRICE *(100MODEL.MODEL_PRICE * - - (100 - SALE.SALE_SALE_DISCOUNT)/100))SALE.SALE_SALE_DISCOUNT)/100))ELSE 0 END )

SALE.SALE_SALE_DISCOUNT)/100))ELSE 0 END )ELSE 0 END)

sum(CASE WHEN year(SALE.SALE_DATE) =

sum( CASE WHEN {fn year(

sum(CASE WHEN to_char(SALE.SALE_DATE,'YYYY')

SalesRevenue2004

2004 THEN

SALE.SALE_DATE )} = 2004

='2004' THEN (SALE_MODEL.SALE_QTY

(SALE_MODEL.SALE_QTY *THEN (SALE_MODEL.SALE_QTY ** MODEL.MODEL_PRICE *(100

MODEL.MODEL_PRICE *(100MODEL.MODEL_PRICE * - - (100 - SALE.SALE_SALE_DISCOUNT)/100))



ELSE 0 END)SALE.SALE_SALE_DISCOUNT)/100))ELSE 0 END )

SALE.SALE_SALE_DISCOUNT)/100))ELSE 0 END )

sum(CASE WHEN FINANCE_PERIOD.FP_YEAR

sum( CASE WHEN FINANCE_PERIOD.FP_YEAR


SalesRevenue

='FY03-04'='FY03-04'

='FY03-04'

forFY03-04

THEN (SALE_MODEL.SALE_QTY *


THEN (SALE_MODEL.SALE_QTY

MODEL.MODEL_PRICE * * MODEL.MODEL_PRICE *(100

MODEL.MODEL_PRICE *(100(100 -

- -

SALE.SALE_SALE_DISCOUNT)/100))ELSE 0 END )

SALE.SALE_SALE_DISCOUNT)/100))



sum( CASE WHEN FINANCE_PERIOD.FP_YEAR


SalesRevenue

='FY04-05'='FY04-05'='FY04-05'

287Alternative SQL syntaxes for other RDBMS—Learner’s Guide


THEN (SALE_MODEL.SALE_QTY

forFY04-05


THEN (SALE_MODEL.SALE_QTY *MODEL.MODEL_PRICE *

* MODEL.MODEL_PRICE *(100MODEL.MODEL_PRICE *(100

(100 - -

- SALE.SALE_SALE_DISCOUNT)/100))ELSE 0 END )

SALE.SALE_SALE_DISCOUNT)/100))


Microsoft AccessObject Name

CLIENT.CLIENT_LASTNAME +', '+ CLIENT.CLIENT_FIRSTNAMEClient Name

MODEL.MODEL_NAME +' '+ MODEL.MODEL_TRIM +' '+ MODEL.MODEL_ENGINEModel

'Calendar Year ' + format(SALE.SALE_DATE,'YYYY')Sale Year

'Q' + format(SALE.SALE_DATE,'Q')Sale Quarter

format(SALE.SALE_DATE,'Mmm')Sale Month

'Calendar Year ' + format(RENTAL.SALE_DATE,'YYYY')Rental Year

'Q' + format(RENTAL.SALE_DATE,'Q')Rental Quarter

format(RENTAL.SALE_DATE,'Mmm')Rental Month

sum(IIf{fn year(SALE.SALE_DATE )} = 2003,(SALE_MODEL.SALE_QTY * MODEL.MODEL_PRICE *(100-SALE.SALE_SALE_DISCOUNT)/100)),0))

Sales Revenue 2003

sum(IIf{fn year(SALE.SALE_DATE )} = 2004,(SALE_MODEL.SALE_QTY * MODEL.MODEL_PRICE *(100-SALE.SALE_SALE_DISCOUNT)/100)),0))

Sales Revenue 2004

sum(IIf(FINANCE_PERIOD.FP_YEAR ='FY03-04',(SALE_MODEL.SALE_QTY * MODEL.MODEL_PRICE *(100-SALE.SALE_SALE_DISCOUNT)/100)),0))

Sales Revenue forFY03-04

sum(IIf(FINANCE_PERIOD.FP_YEAR ='FY04-05',(SALE_MODEL.SALE_QTY * MODEL.MODEL_PRICE *(100-SALE.SALE_SALE_DISCOUNT)/100)),0))

Sales Revenue forFY04-05


Answer Key

This section contains the answers to the reviews and/or activities for the applicable lessons.

289Answer Key—Learner’s Guide


Quiz: Understanding BusinessObjects universesPage 28

1. What are the two main panes in Designer?

Answer: Universe pane, Structure pane

2. What are the three ways to issue commands in Designer?

Answer:menu options, toolbar buttons, right-click drop-down menus

3. Where can you define what specific information about the universe gets printed?

Answer: Under Tools ➤ Options ➤ Print/PDF


Quiz: Creating the course universePage 53

1. Information about universe administration appears on theUniverse Parametersdialog box.Under which tab can you find this information?

Answer: Summary tab

2. Can a universe and its content be embedded in another universe?

Answer: Yes, you can set this up in the Links tab of the Universe Parameters dialog box.Remember that both universes must reference the same database account or targeted datasource.

3. If you want to distribute the completed universe to the user population using theBusinessObjects repository, which type of connection should you use?

Answer: Use a secured connection.


Quiz: Building the universe structurePage 90

1. A schema contains two elements. What are they?

Answer:○ Tables○ Joins

2. What are three reasonswhyusing the automatic detection routine for setting join cardinalitiesis not recommended?

Answer:○ Cardinality is based on logic. The automatic detection routine uses physical cardinality,

and runs a physical count on the values in both columns being joined. You may getincorrect results if the physical count does not return the same result as a logical analysisof the data.

○ The algorithm used by the automatic detection routine assumes that you have sufficientquantity of data in both tables to be representative in ratio to the database in a liveenvironment. If you are designing against a test database, for example, with only arepresentative sampling of data, because the routine runs a physical count, it could giveyou the incorrect answer.

○ The automatic detection routine runs three subsequent queries at the target database perjoin, which may take a very long time for large databases.

3. What type of join is created by default between two tables?

Answer: The default join type is equi-join.


Quiz: Creating dimension objectsPage 117

1. Which of the three types of objects contain aggregate functions that map to statistics in thedatabase?

Answer:Measure objects

2. When you are testing objects, what are the three things for which you need to test?

Answer:○ Do the objects exist? If not, youmay have forgotten to save your universe since the object

you are testing was created.○ Does the SQL appear correct?○ Are the results of the query correct?

3. If each object maps to a column or function in a target database, when used in a query, whatkind of statement does the object infer?

Answer: A SELECT statement


Quiz: Creating measure objectsPage 130

1. Measure objects are very flexible because they are semantically dynamic. What does thismean?

Answer: This means that the values they return in a query will vary depending on thedimension and detail objects that are used with them.

2. Measure objects are created in the same way as a dimension or detail object. However, theobject properties differ in two ways. What are they?

Answer: The object properties differ as follows:○ The Data Type field must be set to Number.○ The Select field must include an aggregate function.


Quiz: Using lists of valuesPage 144

1. By default what values are contained in a list of values (LOV)?

Answer: An LOV is a list associated with an object that, by default, contains all the distinctvalues from the fields in the database for that object.

2. What are three things that a universe designer should keep inmindwhen decidingwhetherto associate an LOV with an object?

Answer:○ Because an LOV is based on a SELECT DISTINCT query that is sent to the target database,

associating an LOV will have implications for the efficiency of Web Intelligence.○ The only purpose for creating an LOV is to assist the end user in choosing an operand

value for a condition. If the LOV does not do this, there is no point in associating it withthe object.

○ Unless the LOV is based on a personal file and not a query, the list will only hold valuesthat exist within the database.

3. For what types of objects is it recommended not to provide an LOV?

Answer: It is recommended that you do not provide an LOV for the following types ofobjects:○ All measure objects.○ Any object where the LOV will consist of a large number of values.○ Any object where the list on its own would be meaningless.


Quiz: Resolving loops in a universePage 176

1. What is the first step in resolving loops?

Answer: Detecting cardinalities

2. What causes a loop?

Answer: A loop is a join path issue that arises from the way that lookup and fact tables arerelated in a relational database. Loops can produce instances where a query returns too fewrows of data.

3. What are the two main methods of resolving loops?

Answer:○ Aliases○ Contexts

4. What are the three types of queries you can use to test your contexts?

Answer:○ Inferred○ Incompatible○ Ambiguous


Quiz: Resolving SQL trapsPage 205

1. A chasm trap can occur when:

Answer:1. Two joins from many-to-one-to-many converge on a single table.

2. The query includes objects based on the two “many” tables.

3. There are multiple rows returned for a single dimension value.

2. Describe two ways to resolve chasm traps.

Answer:1. Create a context for each fact table. This solution works in all cases.

2. Modify the SQL parameters for the universe so you can generate separate SQL queriesfor each measure. This solution only works for measure objects. It does not generateseparate queries for dimension or detail objects.

3. Describe three ways to resolve fan traps.

Answer:1. Alter the SQL parameters for the universe. This only works for measure objects. This

resolution works the same for chasm and fan traps.

2. Create an alias for the table containing the initial aggregation, and then use DetectContexts (Tools > Detect Contexts) to detect and propose a context for the alias table anda context for the original table. This is themost effectiveway to solve the fan trap problemas it will work with measure and dimension objects.

3. Avoid the fan trap in the first place by using the same level of granularity.


Quiz: Applying restrictions on objectsPage 219

1. What is a restriction?

Answer: A restriction is a condition in SQL that sets criteria to limit the data returned bya query.

2. Explain two drawbacks of using restrictions at the object level.

Answer:○ Youwould get a confusing proliferation of objects for end users because youwould then

need a French Clients object, a German Clients object, and so on.○ As these objects would all represent alternate restrictions, you would not be able to

construct a logical default hierarchy (which end users make use of when drilling down).○ Although the UK Clients example is fairly clear, in many cases the restriction will not be

obvious to the user simply from the name of the object. The details of theWHERE clauseare not shown in the User module.

○ If two or more similarly restricted objects are included in the same query, the conflictbetween the WHERE clauses will cause no data to be returned.

3. When should you use self-restricting joins?

Answer:Use self-restricting joins to apply restrictions to tableswhen youwant the restrictionto apply irrespective of where the table is used in the SQL. This method is ideal when atable uses a flag to switch between two or more domains.


Quiz: Using @functions with objectsPage 232

1. What parameter does the @select require?

Answer: @select requires the path of the existing object to be dynamically linked to.

2. True or False. You can use the @where function in a condition object to point to an object,but not the other way round.

Answer: True

3. What function is used to create an interactive object that causes amessage to appear at queryruntime, that asks the user for specific input?

Answer:b. @ prompt

4. In the @prompt two parameters are mandatory and three are optional. What parameters areoptional?

Answer:○ LOV pointer or hard-coded list○ Mono or Multi○ Free or Constrained


Quiz: Using hierarchiesPage 254

1. Select the hierarchy that is based on the order of the objects within the class.

Answer:b. Default

2. What are two advantages of Automatic Time Hierarchies?

Answer:1. It is a fairly quick and easy way to set up a Time Hierarchy.

2. It automatically creates an SQL Select clause using the appropriate scalar function or theRDBMS of the target database.


Quiz: Derived tables and indexesPage 270

1. What part of the SQL expression does Designer use to create column names in the derivedtable?

Answer: It uses an alias (in SQL) to create column names.

For example: count(Region.Region_ID) as number_of_regions.

2. When you insert a derived table and insert joins, what happens if you do not add the newjoin to the appropriate context?

Answer:○ When you parse the derived table’s SQL, it will generate an exception.○ When you run a query, the derived table will create a Cartesian product.○ The objects you create from the derived table will be incompatible with objects from any

of the existing contexts.

3. How do you apply index awareness on a universe object?

Answer:Go to the Keys tab of the Edit Properties dialog box for the object youwant tomakeindex aware.

4. How can index awareness improve query performance?

Answer: It can improve query performance by taking advantage of indexes on key columnsin the data source.


Notes

Notes

Notes

Notes

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