Principles of Information Systems, Seventh Edition2 The database approach to data management...

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Principles of Information Systems, Seventh Edition 2

• The database approach to data management provides significant advantages over the traditional file-based approach

• A well-designed and well-managed database is an extremely valuable tool in supporting decision making

• The number and types of database applications will continue to evolve and yield real business benefits

Introduction

• Database management system (DBMS): group of programs that manipulate database and provide interface between database and users

• Database administrator (DBA): a skilled information systems professional who directs all activities related to organization’s database

The Traditional Approach Versus the Database Approach

• Traditional approach: separate data files are created and stored for each application program

• Results in data redundancy: duplication of data in separate files

• Data redundancy conflicts with data integrity (the degree to which the data in any one file is accurate)

• Database approach: approach whereby a pool of related data is shared by multiple application programs; offers significant advantages over traditional file-based approach

Table 5.1: Advantages of the Database Approach

Table 5.1: Advantages of the Database Approach (continued)

Table 5.2: Disadvantages of the Database Approach

Popular Database Management Systems

• Popular DBMSs for end users include Microsoft’s Access and Corel’s Paradox

• The complete database management software market includes databases by IBM, Oracle, and Microsoft

• Examples of open-source database systems: PostgreSQL and MySQL

• Many traditional database programs are now available on open-source operating systems

Database Applications: Linking the Company Database to the Internet

• Corporate databases can be accessed by customers, suppliers, and company employees through:

• The Internet

• Intranets

• Extranets

Data Resource Management

Chapter 3

What about this concerning DRM?

• “I have traveled the length & breadth of this country and talked with the best people, and I can assure you that data processing is a fad that won’t last out the year”.• The editor in charge of business books for Prentice Hall

(1957)

What about this concerning DRM?

• “It is a capital mistake to theorize before one has data”. • Sir Arthur Conan Doyle (1892)

• Sherlock Holmes

Database Functions• 2. Transform data into information

• 3. Provide security – Who has access. Part of Sarbox.

• 4. Allow multi-user access

• 5. Allow programming & Query Lang. ability

Data Resource Management• Data is a resource• Data must be organized (table)• Data must be managed

• (backup & retrieval• Add records• Delete records

• Business survival depends on information regarding internal & external environ.

• What is the external environment?• Government: Fed., state, city, county

New laws, changes in laws, mandates, compliance• World Economics

• Politics

• Competitors

• Demographics

• Suppliers

• Technology (hardware, software, etc.

• Customers

• A managerial activity• Applies IS technology to managing data resources to

• meet needs of business stakeholders.• IS technology (from above)

• DBMS• Data warehousing• Data mining

• Center for Data Integrity (CDI)

Foundation Data Concepts (continued)

• Database• Integrated collection of logically related data elements

• Consolidates records into a common pool of data elements

• Data is independent of the application program using them and type of storage device

Foundation Data Concepts (continued)Files (table)

• A group of related records

• Records• Related fields of data

• Collection of attributes that describe an entity

Foundation Data Concepts• Levels of data

• Field• Groupings of characters

• Represents an attribute of some entityEntity

» Person» Place» Object» event

• Character• Single alphabetical, numeric, or other symbol

Logical Data Elements – What are they?

Logical Data Elements• Compare the previous figure with the data that was

organized before computers.

• Is that older system still used?

• Since data entry bookkeeping?

• Can you have more than one database in your organization? If so, why would you want this?• One database—1 or more tables

• Separate databases– 1 or more tables

Logical Data Elements

• Who will organize the data (database, tables, records, fields, entities) in your organization.• 3rd generation language – Very procedural

• 4th generation language – managers can use it.

• Who will use the data in your organization?

• Who will maintain the data in your org.’s database?

Types of Databases• Operational

• Supports business processes and operations

• Also called subject-area databases, transaction databases, and production databases

• Examples• HR database

• Inventory database

• Customer database

• E-commerce databases

Types of Databases (continued)• External

• Available for a fee from commercial sources or with or without charge on the Internet or World Wide Web or your supplier DB’s.

• Sources are almost endless

• External can be download into DBMS Remember that DBMS is a decision support tool. Example?

• Infor. From the DBMS can be downloaded in to a variety of applications for analysis.

Excel. Also a decision support tool.

Example?• Database inform. can be accessed by Excel. Excel

information can be accessed by DB.

Data Warehouses and Data Mining

• Data warehouse• Stores data extracted from operational, external, or

other databases of an organization

• Central source of “structured” data

• May be subdivided into data marts• Subsets of data that focus on specific aspects of the co.,

e.g., by department or process.

Data warehouse• Data acquisition

• This process includes activities• Consolidating data from several sources

• Filtering out unwanted data

• Correcting incorrect data

• Converting data to new data types

• The data is then stored so that it can be moved into the enterprise warehouse

Data Warehouse

• Enterprise warehouse• Can then be moved into data marts or

• To analytical data stores• Holds data in a more useful form for certain types of

data so that it can be used by OLAP applications.

• Link to OLAP

Data Warehouses and Data Mining (continued)

• Data mining• A major use of data warehouse databases

• Data is analyzed to reveal hidden correlations, patterns, and trends

• In vast amounts of dataUsually several terabytes of data.

» 4, 000,000,000,000 bytes» Its above gigabytes

Data Mining (continued)

Data mining software uses:• Advanced pattern recognition algorithms

• Variety of math & statistical techniques

• To filter through data to extract previously unknown strategic business information.

• Examples:New or change products

New or change services

Marketing activities

Organizational change/process change

Database Management Approach)

• DBMS serves as an interface between the users and databases. • Controls how databases and objects are

• Created

• Interrogated

• Maintained

• So users can easily access the data in the database

Database Management Approach (continued)

• Database Interrogation • 3rd Generation. Programming languages

• 4th Generation. SQL and then QBE

• Query• Supports ad hoc requests

• Can save queries

• Tells the software how you want to organize the data and what data that you want?

• QBE has a graphical user interface (GUI)

SQL & Natural Languages

Database Management Approach (continued)

• Report Generator• Turns results of a table or query into a useable report

• Can specify a report format.• Examples of report formatting ???• Can these report formats be saved ???• Reports are linked to a table• Can a report also be linked to a query ??? If so, why

would you want to do this ???

Database Maintenance• Database Maintenance

• What is this? 3 simple things that are imp.• Add records

• Delete records

• Change the nature of records

• Why must this occur?

• Who does it, usually?

Section II

• The remaining slides are from information from your text for Chapter 5

Data Structures

• The relationships among the many individual data elements stored in databases are based on one of several logical data structures or models

• DBMS packages are designed to use a specific data structure to provide end users with quck & easy acces to information stored in a DB.

• 5 database structures

Database Structures

• Hierarchical• Early mainframe DBMS packages used this

• Treelike or hierarchical

• All of the relationships are one-to-many

• Used for structured, routine types of transaction processing

• Not very flexible. One-to-many relationships only.

Database Structures (continued)• Network structure

• More complex• Relationships must be specified in advance

• More flexible

• Many-to-many relationship

• More flexible but doesn’t support ad hoc requests well

Database Structures (continued)• Relational structure

• Data elements stored in simple tables

• Relationships do not have to be specified when the database is created.

• Can link data elements from various tables

• Can create new tables of data relationships using parts of data from several tables.

• Very supportive of ad hoc requests but slower at processing large amounts of data than hierarchical or network models

• Easier to maintain

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