Database

In any computer-based IR System, the database is on a machine readable media such as magnetic tapes, or magnetic discs. The database could be created either by key boarding the information (by manual data entry) or by obtaining the database directly on machine-readable form. 

The database in IR Systems contains one or more of the following files: The document descriptions file; 

1. One or more index files, keyword or descriptor files;  
2. Thesaurus or vocabulary file; and 
3. A user-profile file which is used for providing SDI outputs. 

The database is the basis for generating services to the users of the IR Systems and hence plays a crucial role in its organisation.