The Alternate Catalog Mapping (ACM) facility allows you to redirect DB2 catalog queries to shadow tables or views defined over the DB2 system catalog tables. This can greatly improve performance and limit access to the actual DB2 catalog tables.
A large number of the CA Database Management Solutions for DB2 for z/OS products* can easily utilize ACM.
To list, create and maintain ACM select option M - Alt. Catalog Mapping from the CA DB2 Products Main Menu.
Each ACMID is a definition of all catalog tables and their shadow table, like these examples:
SYSIBM - SYSCOLAUTH DB2ADMIN - SYSCOLAUTH
SYSIBM - SYSCOLUMNS DB2ADMIN - SYSCOLUMNS
SYSIBM - SYSCOPY DB2ADMIN - SYSCOPY
SYSIBM - SYSDATABASE DB2ADMIN - SYSDATABASE
SYSIBM - SYSDBAUTH DB2ADMIN - SYSDBAUTH
To use ACM, specify ACM ON and the ACMID on the DB2 Products Main Menu:
Command ACM will display the status of ACM:
Many products also support command ACMON / ACMOFF to toggle between ACM modes.
For details of how to create and maintain ACMIDs please refer to the CA 'DB2 DB Management Common Functions' online manual.
You will see that this is easy to implement including creating shadow objects (database, tables, and indexes) and loading (initializing or updating) the data.
If you run the refresh of ACM tables every night, the ACM tables will be up-to-date and you can avoid contention on the DB2 catalog during normal working hours.