DB2 Version 9.7 for Linux, UNIX, and Windows

cat_cache_overflows - Catalog Cache Overflows monitor element

The number of times that the catalog cache overflowed the bounds of its allocated memory.

Table 1. Snapshot Monitoring Information
Snapshot Level	Logical Data Grouping	Monitor Switch
Database	dbase	Basic
Application	appl	Basic

For snapshot monitoring, this counter can be reset.

Table 2. Event Monitoring Information
Event Type	Logical Data Grouping	Monitor Switch
Database	event_db	-
Connection	event_conn	-

Usage

Use this element with thecat_cache_size_top monitor element to determine whether the size of the catalog cache needs to be increased to avoid overflowing.

Catalog cache space is reclaimed by evicting table descriptor information for tables, views, or aliases, or authorization information that is not currently in use by any transaction.

If the value of the cat_cache_overflows monitor element is large, the catalog cache may be too small for the workload. Enlarging the catalog cache may improve its performance. If the workload includes transactions which compile a large number of SQL statements referencing many tables, views, aliases, user-defined functions, or stored procedures in a single unit of work, then compiling fewer SQL statements in a single transaction may improve the performance of the catalog cache. Or if the workload includes binding of packages containing many SQL statements referencing many tables, views, aliases, user-defined functions, or stored procedures, you can try splitting packages so that they include fewer SQL statements to improve performance.