Administration Guide

Definition of System Catalog Tables

A set of system catalog tables is created and maintained for each database. These tables contain information about the definitions of the database objects (for example, tables, views, indexes, and packages), and security information about the type of access that users have to these objects. These tables are stored in the SYSCATSPACE table space.

These tables are updated during the operation of a database; for example, when a table is created. You cannot explicitly create or drop these tables, but you can query and view their content. When the database is created, in addition to the system catalog table objects, the following database objects are defined in the system catalog:

• A set of user-defined functions (UDFs) is created in the SYSFUN schema. For more information about these system-created functions, refer to the SQL Reference manual.
• A set of read-only views for the system catalog tables is created in the SYSCAT schema. Refer to "Catalog Views" in the SQL Reference for information about these views.
• A set of updatable catalog views is created in the SYSSTAT schema. These updatable views allow you to update certain statistical information to investigate the performance of a hypothetical database, or to update statistics without using the RUNSTATS utility. Refer to "Updatable Catalog Views" in the SQL Reference for information about these views.

After your database has been created, you may wish to limit the access to the system catalog views, as described in Securing the System Catalog Views.