FIS - Chapter 5

Database

Organized collection of data

Database management system (DBMS)

Group of programs that manipulate the database.

Provide an interface between the database and its users and other application programs.

Can reference a schema to find where to access the requested data in relation to another piece of data

can act as front-end or back-end applications

Database Administrator (DBA)

Skilled IS professional who directs all activities related to an organization’s database.

Works with users to decide the content of the database – Works with programmers as they build applications to ensure that their programs comply with database management system standards and conventions

Data Administrator

Responsible for defining and implementing consistent principles for a variety of data issues

Data Management

without data and the ability to process the data: an organization could not successfully complete most business activities.

Bit

circuit that is either on or off

Byte

typically made of eight bits

Character

basic building block of information

Field

name, number, or combination of characters that describes an aspect of a business object or activity

Record

collection of related data fields

File

collection of related records

Database

collection of integrated and related files

Entity

general class of people, places, or things (objects) for which data is collected, stored, and maintained. Is described, records.

Attribute

characteristic of an entity. Fields.

Data Item

specific value of an attribute.

Key

field or set of fields in a record that is used to identify the record.

Primary Key

field or set of fields that uniquely identifies the record.

Foreign Key

refers to the primary key in another table.

Traditional Approach

each distinct operational system used data files dedicated to that system

Database Approach

pool of related data is shared by multiple application programs.

Data Modeling

Building a database

Logical design

Abstract model of how data should be structured and arranged to meet an organization’s information needs

Physical design

Starts from the logical database design and finetunes it for performance and cost considerations

Enterprise data modeling

Starts by investigating the general data and information needs of the organization at the strategic level

Entity-relationship (ER) diagrams

Data models that use basic graphical symbols to show the organization of and relationships between data

Relational model

Describes data using a standard tabular format

Each row of a table represents a data entity (record)

Columns of the table represent attributes (fields)

Domain

Allowable values for data attributes

Selecting

Eliminates rows according to certain criteria

Projecting

Eliminates columns in a table

Joining

Combines two or more tables

Linking

Manipulating two or more tables that share at least one common data attribute

Flat file

Simple database program whose records have no relationship to one another

Single user

Only one person can use the database at a time

Examples: Access, FileMaker Pro, and InfoPath

Multiple users

Allow dozens or hundreds of people to access the same database system at the same time

Examples: Oracle, Sybase, and IBM

Schema

Used to describe the entire database

Can be part of the database or a separate schema file

Concurrency control

Method of dealing with a situation in which two or more users or applications need to access the same record at the same time