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Database Management

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Identify file maintenance techniques

Discuss the terms character, field, record, and table

Describe characteristics of relational and object-oriented databases

Explain how to use aquery language

Understand how Webdatabases work

Discuss the functions most common to DBMSs

Identify the qualities of valuable information

Understand the concept of a data warehouse

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Database

AKA Database Management System (DBMS)

Collection of Data Organized for Quick Access, Retrieval, & Use

Databases Allow You to

Create Database

Add, Change, & Delete Data

Sort & Query Database

Print Reports

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Data Integrity

Degree to Which Data is Correct

When Database Contains Errors, it Loses Integrity

GIGO (Garbage In, Garbage Out)

Cannot Create Correct Information From Incorrect Data

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Qualities of Valuable Information

Accurate Verifiable Timely Organized Accessible Useful Cost-effective

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Data Hierarchy

Database Contains Files File Contains Records Record Contains Fields Field Contains Characters

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Field

Combination of One or More Characters

Smallest Unit of Data User Accesses

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Field Characteristics

Field Name Uniquely Identifies Each Field Data Type

Text Numeric Autonumber Currency Date Memo Hyperlink Object

Field Size

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Record

Group of Related Fields

Key Field

AKA Primary Key

Uniquely Identifies Each Record

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Table / File

Collection of Related Records Stored on Disk

Each Record in File Contains Same Fields

Each Field Contains Different Data

Database Composed of Group of Related Tables / Files

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Popular DBMS

PC, midrange server, mainframeIBM CorporationDB2

PC, midrange server, mainframeIBM CorporationInformix

ServerMicrosoft CorporationSQL Server

PC, midrange server, PDASybase Inc.Sybase

PC, midrange server, mainframe, PDAOracle CorporationOracle

PC, midrange server, mainframeComputer Associates International, Inc.

Ingres

PC, server, PDAMicrosoft CorporationAccess

Computer TypeManufacturerDatabase

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File Maintenance

Procedure That Keeps Data Current Add Records

When You Obtain New Data Change Records

Correct Inaccurate Data Update Existing Data

Delete Records Record No Longer Needed

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Validation

Process of Comparing Data with a Set of Rules

Find Out if Data is Correct

Reduce Data Entry Errors

Enhance Data Integrity

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Validation

Types Alpha / Numeric

Correct Data Type Entered

Range Number is in Specified Range

Completeness Required Field Contains Data

Consistency

Check Digit

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Data Dictionary

Contains Data About Each File in Database Contains Data About Each Field in Those Files

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Form

On Screen Window Provides Areas for Entering / Changing Data in a

Single Record

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Report Generator

Generates Report Without User’s Knowledge of Programming

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Report Types

Detailed

Summary

Consolidates Data

Exception

Identifies Data Outside of Norm

Conditions Define Status Range

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Query

Request Specific Data from Database SQL (Structured Query Language)

Allow Users to Specify Data to Display, Print, or Store QBE (Query By Example)

Retrieves Records that Match Criteria Entered in Form Fields

QBE Criteria

Result

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File Processing System

Each Department Has Own Set of Files Records in One File May Not Relate to Records

in Other Files Weakness

Redundancy Same Fields Stored in Multiple Files

Isolated Difficult to Access

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Database System

Many Programs & Users Can Share Data Secures Data

Only Authorized Users Can Access Certain Data Can View Data But Not Update or Change It

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Storage Differences

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Database System Strengths

Reduced Redundancy

Improved Integrity

Shared Data

Easier Access

Reduced Development Time

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Data Model

How Database Organizes Data

Defines How Users View Data

Types

Relational

Object-oriented

Multidimensional

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Relational Database

Stores Data in Tables

Consist of Rows & Columns

Each Row has Primary Key

Related Tables Must Havea Common Field tabletable

columncolumn

relationshipsrelationships

rowrow

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Object-oriented Database (OODB)

Stores Data in Objects Can Contain Both Data & Activities That Read /

Process Data Advantages

Can Store More Types of Data Can Access Data Faster

Example Multimedia Database

Store Images, Audio, and/or Video

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Multidimensional Database

Stores Data in Dimensions

Multiple Dimensions Allow Users to Analyze Any View of Data

AKA Hypercube

Advantages

Consolidates Data Much Faster than Relational Database

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Multidimensional Database

Data Warehouse From Multiple Databases

Comprehensive Data Required to Analyze Data Across Enterprise

Examples Data Mining

Process of Finding Patterns & Relationships Among Data Click Stream

Collection of Every Action Users Makes in Web Site

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Database Development Guidelines