Information on storage media and attributes for database-specific files (the CAT-REC file, CAT-LOG files, DA-LOG files and PBI file or the HSMS work file) is stored in the media table in so-called “media records”. The first media record for the CAT-REC file and the first media record for the CAT-LOG files is created when the utility statement CREATE CATALOG executes (see section “Creating the database's catalog space” ).
The database administrator creates the first media record for DA-LOG files and the first media record for PBI file or the HSMS work file with the utility statement CREATE MEDIA DESCRIPTION.
The execution of the statement CREATE MEDIA DESCRIPTION for a specific file type is rejected if the media table already contains an entry for the relevant file type.
The media table can be maintained (i.e., further media records can be added or media records can be removed) with the aid of the utility statements ALTER MEDIA DESCRIPTION and DROP MEDIA DESCRIPTION.