12121212CHAPTER

DATABASES

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Competencies

Distinguish between the physical and logical view of data

Describe how data is organized

Describe databases

Describe the five data models

Distinguish among the different databases

Recognize strategic database uses & security concerns

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Data

Facts or observations about people, places, things, and events

Two ways to view data

Physical view

Logical view

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Data Organization

Character

Field

Record

File

Database

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Key Field

Unique identifier

Common examples

Social security number

Driver’s license

Credit card account

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Batch Versus Real-Time Processing

Batch processing -- later

Real-time processing -- now

Batch Processing

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Real-Time Processing

12-8

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Databases

Sharing – one department to another

Security – passwords to access

Less data redundancy

Data integrity

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Database Management

DBMS engine

Data definition subsystem

Data manipulation subsystemQuery-by-example

Structured query language (SQL)

Application generation subsystem

Data administration subsystem

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DBMS Structure

Hierarchical database

Network database

Relational database

Multidimensional database

Object-oriented database

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Hierarchical Database

Fields or records are structured in nodes

Nodes are point connected like branches

One parent per node

Parent has several child nodes

Airlines may use a hierarchical

database

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Network Database

Hierarchical node

arrangement

Many-to-many

relationship

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Relational Database

Most flexible

Data stored in table or relation

Tables related via a common data item

Easy to use

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Multidimensional Database

A variation and an extension of the relational model

Includes a hyper cube

Good for representing complex relationships

Advantages over relationalConceptualization

Processing speed

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Object-Oriented Database

Works with unstructured data Photographs

Graphics

Audio

Video

Objects contain both data and instructions

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Types of Databases

Individual or microcomputer database

Company or sharedOperational

User

Distributed

Proprietary

Web database

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Database Uses and Issues

Strategic usesSpecial type of database called data warehouse

Data mining used to search database

SecurityDatabases are valuable

Protection necessary

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A Look to the FutureXperanto

Enhancement to searching for data

Access to structured (relational databases) and unstructured data (word processing and spreadsheet files)

12-19

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Key Terms

application generation subsystem (334)attribute (329)batch processing (330)CGI (Common Gateway Interface) (341)character (329)child node (335)class (338)common data item (337)

common operational database (340)

common user database (340)

company database (339)

data (328)

data administration subsystem (334)

data bank (340)

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Key Terms

database (330)

database administrator (DBA) (334)

database management system (DBMS) (333)

data definition subsystem (333)

data dictionary (333)

data integrity (332)

data maintenance (334)

data manipulation subsystem (333)

data mining (342)

data model (334)

data redundancy (332)

data warehouse (342)

DBMS engine (333)

12-21

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Key Terms

distributed database (340)

entity (329)

field (329)

file (330)

firewall (343)

hierarchical database (335)

hyper cube (337)

individual database (339)

information utility (340)

key field (330)

logical view (328)

many-to-many relationship (335)

method (338)

microcomputer database (339)

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Key Terms

multidimensional database (337)

network database (335)

node (335)

object (338)

object-oriented database (335)

one-to-many relationship (335)

online processing (331)

parent node (335)

physical view (328)

pointer (335)

primary field (330)

processing rights (334)

proprietary database (340)

query-by-example (334)

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Key Terms

real-time processing (331)

record (330)

relation (336)

relational database (336)

shared database (336)

structured query language (SQL) (334)

Web database (341)

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FAQs

What is data? Name the different types of data.

What is the difference between a physical and a logical view?

What is a key field?

What is a relational database?

What are the five classifications of databases?

What is data mining?

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Discussion Questions

Explain how data is organized.

Discuss the difference between batch and real-time processing.

Discuss the advantages of using a database.

Describe the five DBMS models.