Discovering Computers Fundamentals Fifth Edition Chapter 9 Database Management

Discovering Computers

FundamentalsFifth Edition

Chapter 9 Database Managem

ent

Chapter 9 Objectives

Discuss the functions common to most DBMSs

Discuss the functions common to most DBMSs

Identify the qualities of valuable information

Identify the qualities of valuable information

Discuss the terms character, field, record, and file

Discuss the terms character, field, record, and file

Identify file maintenance techniquesIdentify file maintenance techniques

Differentiate between a file processing system approach and the database approach

Differentiate between a file processing system approach and the database approach

Describe characteristics of relational, object-oriented, and

multidimensional databases

Describe characteristics of relational, object-oriented, and

multidimensional databases

Explain how to interact with Web databasesExplain how to interact with Web databases

Discuss the responsibilities of database analysts and administrators

Discuss the responsibilities of database analysts and administrators

Next

Define the term, databaseDefine the term, database

Add, change,

and delete data

Add, change,

and delete data

CreatedatabaseCreate

database

Sort and

retrieve data

Sort and

retrieve data

Createforms and

reports

Createforms and

reports

Databases, Data and InformationWhat is a database?

p. 332 Next

Database software allows you to

Database software allows you to

Collection of data organized so

you can access, retrieve, and

use it

Collection of data organized so

you can access, retrieve, and

use it

Database software also called database management system

(DBMS)

Database software also called database management system

(DBMS)

Data and Information

How are data and information related?

p. 332 - 333 Fig. 9-1 Next

Data is raw facts Information is data that is organized and meaningful Computers process data into information


What is data integrity?

p. 333 Next

Defines the quality of the data Garbage in, garbage

out (GIGO)—computer phrase that means you cannot create correct information from incorrect data

Garbage out

Garbage in

Data integrity is lost


What are the qualities of valuable information?

p. 334 Next

The Hierarchy of Data

What is a hierarchy?

p. 334 - 335 Fig. 9-2 Next

Database contains files, file contains records, record contains fields, field contains characters


What is a field?

p. 335 Fig. 9-3 Next

Combination of one or more characters

Smallest unit of data user accesses Field name uniquely identifies each

field Field size defines the maximum

number of characters a field can contain

Data type specifies the kind of data a field contains

Yes/NoYes/Noonly the values Yes or No (or True or False)

HyperlinkHyperlinkWeb address that links to document or Web page

ObjectObjectphotograph, audio, video, or document created in other application such as word processing or spreadsheet


What are common data types?

p. 335 Next

CurrencyCurrencydollar and cent amounts or

numbers containing decimal values

DateDatemonth, day, year, and

sometimes time

MemoMemolengthy text entries

TextText(also called

alphanumeric)—letters, numbers, or special

characters

NumericNumericnumbers

only

AutoNumberAutoNumberunique number automatically assigned to each new record


What is a record?

p. 336 Next

Group of related fields

Key field, or primary key, uniquely identifies each record

Database Management Systems

What is a data dictionary?

p. 343 Fig. 9-12 Next

Contains data about each file in database and each field within those files


What is a query?

p. 344 Fig. 9-13 Next

Request for specific data from a database

Query language consists of simple, English-like statements that allow users to specify data to display, print, or store


What is a form?

p. 345 Next

Window on screen that provides areas for entering or changing data in database

Used to retrieve and maintain data in a database Well-designed forms should validate data as it is

entered


What is a report generator?

p. 346 Fig. 9-15 Next

Allows user to design a report on screen, retrieve data into report design, then display or print reports

Also called report writer


What are popular database management systems (DBMSs)?

p. 343 Fig. 9-11 Next


What are backup and log?

p. 346 Next

Backup is a copy of the entire database A continuous backup is a backup plan in which all

data is backed up whenever a change is made Log is a listing of activities that change database

contents A recovery utility uses the logs and/or backups to

restore a database when it becomes damaged or destroyed

Maintaining Data

What is validation?


Process of comparing data with a set of rules to find out if data is correct

Reduce data entry errors and enhance data integrity before program writes data on disk

Consistency Check tests for logical relationship between two or more fields

Consistency Check tests for logical relationship between two or more fields

Maintaining Data

p. 339 - 340 Next

What are the types of validity checks?

Range Check determines whether number is within specified range

Range Check determines whether number is within specified range

Completeness Checkverifies that a required field contains data

Completeness Checkverifies that a required field contains data

Check Digit number(s) or character(s) appended to or inserted into a primary key value to confirm accuracy of primary key value

Check Digit number(s) or character(s) appended to or inserted into a primary key value to confirm accuracy of primary key value

Alphabetic/Numeric Check ensures correct type of data entered

Alphabetic/Numeric Check ensures correct type of data entered

Isolated data—data stored

in separate files so it is difficult to

access

Isolated data—data stored

in separate files so it is difficult to

access

File Processing Versus DatabasesWhat is a file processing system?

p. 341 Next

Data redundancy—

same fields stored in

multiple files

Data redundancy—

same fields stored in

multiple files

Each department or

area within organization

has own set of files

Each department or

area within organization

has own set of files

May have weaknessesMay have

weaknesses

Records in one file may not relate to

records in any other file

Records in one file may not relate to

records in any other file

File Processing Versus DatabasesWhat is the database approach?


Many programs and users can share data in database Secures data so only authorized users can access

certain data

File Processing Versus DatabasesWhat are the strengths of the database approach?

p. 342 Next

Reduced data

redundancy

Reduced data

redundancy Improved data

integrity

Improved data

integrityShared

dataShared

dataEasier accessEasier access

Reduced development

time

Reduced development

time


What is data security?

p. 346 Next

user can view data, but cannot change it

user can view data, but cannot change it

DBMS provides means to ensure only authorized users can access data at permitted

times

DBMS provides means to ensure only authorized users can access data at permitted

times

Access privileges

define activities that a specific

user or group of users can perform

Access privileges

define activities that a specific

user or group of users can perform

user can view and

change data

user can view and

change data

Relational, Object-Oriented, and Multidimensional Databases

What is a data model?

p. 347 Next

Rules and standards that define how database organizes data

Defines how users view organization of data Three popular data models

Relational Object-oriented Multidimensional


What is a relational database?

p. 347 - 348 Fig. 9-16 Next

Stores data in tables that consist of rows and columns Each row has primary key Each column has unique name

Stores data relationships Uses specialized terminology


What is a relationship?

p. 348 Fig. 9-17 Next

Connection within data


What is Structured Query Language (SQL)?

p. 348 - 349 Fig. 9-18 Next

Allows you to manage, update, and retrieve data Has special keywords and rules included in SQL

statements


What is an object-oriented database (OODB)?

p. 349 Next

Advantages

Often uses object query language (OQL)

Stores data in objectsObject is item that contains data, as well as actions that read or process data

Stores more types of dataCan access data fasterProgrammers can reuse

objects

What is a multidimensional database?


p. 349 Next

Stores data in dimensions

Allow users to analyze any view of data

Can consolidate data much faster than relational database


What is a data warehouse?

p. 349 Next

Data mart is smaller version of Data mart is smaller version of data warehousedata warehouse

Uses Uses multidimensional multidimensional

databasesdatabases

Huge database system that stores and manages data Huge database system that stores and manages data required to analyze historical and current required to analyze historical and current

transactionstransactions

Quick and efficient Quick and efficient way to access large way to access large

amounts of dataamounts of data

Web Databases

What is a Web database?

p. 350 Fig. 9-19 Next

Database you access through the Web by filling in a form on a Web page

Usually resides on a database server, a computer that stores and provides access to a database

Database Administration

What is the role of the database analyst and administrator?

p. 351 Next

Database analyst (DA)Database analyst (DA) Database administrator (DBA)Database administrator (DBA) Decides proper placement

of fields, defines relationships, and identifies users’ access privileges

Creates and maintains data dictionary, manages database security, monitors database performance, and checks backup and recovery procedures

Summary of Database Management

Chapter 9 Complete

How data and information are valuable assets to an organization

How data and information are valuable assets to an organization

Methods for maintaining high-quality data

Methods for maintaining high-quality data

Assessing the quality of valuable information

Assessing the quality of valuable information

Advantages of organizing data in a database

Advantages of organizing data in a database

Various types of databasesVarious types of databases

Role of the database analysts and administrators

Role of the database analysts and administrators

Documents

Discovering Computers Fundamentals Fifth Edition Chapter 9 Database Management