Using catalog indirection with ALTER, Catalog Manager, and Change Manager

Catalog indirection is an optional method of implementing and maintaining these products. To accomplish catalog indirection, the products use aliases that point to a copy of the Db2 catalog.

Catalog indirection allows products to query the Db2 catalog indirectly. Catalog indirection applies only to catalog queries. Any action that changes information in the catalog must operate on the actual catalog, not on a copy of the catalog. For example, when you issue a command through Catalog Manager to update the catalog, the action affects the actual catalog. The Execution Monitor in  ALTER and Change Manager also executes a worklist against the actual catalog. In contrast, the Analysis component in ALTER and  Change Manager can use either the actual catalog or catalog indirection when creating worklists.

General points about catalog indirection are as follows:

• Catalog indirection requires Db2 Version 10 or later in new-function mode.

• The products are set up to access the Db2 catalog directly. After the installation, you can use the Installation System to implement and maintain catalog indirection.

• The aliases that reference the Db2 catalog are hardcoded in the components. You direct the aliases to the catalog or copy during installation by providing information on the Installation System panels.

• You can use the same copy of the catalog for Catalog Manager and Change Manager, or you can implement catalog indirection through separate copies for each product.

• Catalog indirection reduces contention for the Db2 catalog

To install catalog indirection, see Installing.

This section contains the following topics:

• Implement and maintain catalog indirection
• Specify the installation options module
• Specify alias qualifiers during maintenance
• Use a copy of the catalog
• Use a copy of the catalog to reduce catalog contention