Database overview

• "A shared collection of integrated data designed to meet the varied needs of an organisation."

[Ref 119] McFadden,Hoffer

A Database may consist of a file or combination of files containing

• The raw data
• A data dictionary (The data about data, field names, szes, types, etc).
• Basic mechanisms for adding, deleting, modifying and querying the data.(eg. SQL interface, Open database interconnection (ODBC) interface).

In some cases the database management system (DBMS) is "bound" to the database. For example, in a flat-file database.

A database is a collection of integrated data where;

• redundancy (duplication) is controlled (in theory eliminated).
• one or more application may be served
• programs are independent
• a common and controlled approach is used when adding, modifying and retrieving data

The logical description (how we see the data) is independent of the physical description (way it is stored).

Examples:

• MS SQL-Server,
• Used in 4GL's such as Oracle, Informix, Progress, MS-Access.