1: Database Systems: Design, Implementation, and Management

Data

They are raw facts. Building blocks of information which is the bedrock of knowledge.

Information

The result of processing raw data to reveal meaning. Requires context to reveal meaning. Produced by processing data.

Database

It is shared, integrated computer structure that stores a collection of end-user data and metadata.

End-user data

Raw facts of interest to end user.

Metadata

Data about data. Provides description of data characteristics and relationships in data. Complements and expands value of data.

Database Management System (DBMS)

A collection of programs. Manages structure and controls access to data. The intermediary between the user and the database.

Single-user database

Supports only one user at a time.

Multiuser database

Supports multiple users at the same time.

Centralized database

Data located at a single site.

Distributed database

Data distributed across several different sites.

Operational database

Supports a company’s day-to-day operations. Can be transactional or production database,

Data warehouse

Stores data used for tactical or strategic decisions.

Unstructured data

Exist in their original state.

Structured data

Result from formatting. Applied based on type of processing to be performed.

Semistructured data

A type of database that have been processed to some extent.

Extensible Markup Language (XML)

Represents data elements in textual format.

Data processing (DP) specialist

Converted computer file structure from manual system.

Data redundancy

Same data stored unnecessarily in different places.

Data inconsistency

Different and conflicting versions of same data occur at different places.

Data anomalies

Abnormalities when all changes in redundant data are not made correctly.

Database Systems

Consists of logically related data stored in a single logical data repository. May be physically distributed among multiple storage facilities. Also defines, stores, and manages all access paths and components.

1. Hardware

2. Software

3. People

4. Procedures

5. Data

The five major parts of a database system.

Hardware

All the system’s physical devices.

1. Operating System Software

2. DBMS Software

3. Application programs and utility software.

The three types of software.

People

All users of the database system.

Procedures

Instructions and rules that govern the design and use of the database system.

Query Language

Is a nonprocedural language.

Structured Query Language (SQL)

Is the facto query language.

Field

A character or group of characters that has a specific meaning.

Record

A logically connected set of one or more fields that describes a person, place, or thing.

File

A collection of related records.