IMS catalog and directory management
The IMS catalog is a system database that stores the definitions of your databases and program specification blocks (PSBs), as well as other metadata about your databases and application programs.
When the IMS management of application control blocks (ACBs) is enabled, IMS stores the active ACBs in the IMS directory, a collection of system-managed data sets that are an extension of the IMS catalog. The IMS directory data sets include data sets for the ACBs that are active in the IMS system, a staging data set for ACBs that are pending activation.
The IMS catalog and directory management function helps you to manage the IMS catalog and the IMS directory that you need to maintain. If the IMS management of ACBs is not enabled, the IMS catalog and directory management function can be used to analyze ACB libraries instead of the IMS directory.
IMS catalog and directory management business scenarios
- Perform space utilization analysis and view the number of DBDs (databases), PSBs (programs), DBD/PSB objects, and DBD/PSB instances in the IMS catalog database.
- Generate reports to help analyze the databases and applications defined in the IMS catalog and IMS directory.
- Identify obsolete DBDs and PSBs in the IMS catalog database (DBDs and PSBs that are not referred to by the IMS system), and delete them to improve the performance or increase available space in the IMS catalog database.
- Find inconsistencies in IMS catalog and IMS directory.
- Perform impact analysis when either 1) planning for the IMS catalog maintenance or 2) adding a large number of objects to the IMS catalog.
- Verify cross-references between DBDs and PSBs to ensure that relationship integrity is maintained.
- Copy DBD and PSB objects between one IMS system to another IMS system.
- Include and update individual (or bulk) IMS database definitions (DBD) with schema from COBOL or PL/I copybooks during the import process to the IMS catalog.
- Create backups of IMS directory and bootstrap data sets (BSDS) whenever an IMPORT DEFN SOURCE(CATALOG) command is issued, and restore the data sets from the latest backup when needed.