DBMS - Database management system is essentially nothing more than a computerized data-keeping system. Users of the system are given facilities to perform several kinds of operations on such a system for either manipulation of the data in the database or the management of the database structure itself.
Relational databases include the following structures:
Database
A database is a logical grouping of data. It contains a set of related table spaces and index spaces.
Typically, a database contains all the data that is associated with one application or with a group of related applications. You could have a payroll database or an inventory database, for example.
Table
A table is a logical structure made up of rows and columns. Rows have no fixed order, so if you retrieve data you might need to sort the data. The order of the columns is the order specified when the table was created by the databases administrator.
Indexes
An index is an ordered set of pointers to rows of a table. Unlike the rows of a table that are not in a specific order, an index must always be maintained in order by DB2. An index is used for two purposes:
- For performance, to retrieve data values more quickly
- For uniqueness.
ibm.com, 2022. IBM Docs. [online] Ibm.com. Available at: <https://www.ibm.com/docs/en/zos-basic-skills?topic=zos-what-is-database-management-system> [Accessed 9 April 2022].
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