Field

Description

Catalog Cache

Size

Maximum allowed size in KB for the catalog cache. The catalog cache is accessed each time a transaction accesses a table, view or alias. The cache is allocated dynamically from the heap.

The maximum allowed size is determined by database configuration parameter CATALOGCACHE_SZ.

Quality

Indicates percentage at which the data is read from the catalog cache, rather than directly from the hard disk.

This is calculated using the following formula:
(catalog cache lookups - catalog cache inserts) / catalog cache lookups * 100

Lookups

Number of times that the catalog cache was referenced to obtain table descriptor information

Inserts

Number of times that the system tried to insert table descriptor information into the catalog cache

 Overflows

Number of times that an insert into the catalog cache failed due to the catalog cache being full

High-Water Mark

Largest size reached by package cache

Package Cache

Size

Maximum allowed size in KB for the package cache. The package cache contains access plans.
The maximum allowed size is determined by database configuration parameter PCKCACHESZ.

Quality

Indicates percentage at which the data is read from the package cache, rather than directly from the hard disk.

This is calculated using the following formula:
(package cache lookups - package cache inserts) / package cache lookups *100

Lookups

Number of times an application looked for a section in the package cache

Inserts

Total number of times that an access plan was not available for use and had to be loaded into the package cache

Overflows

Number of times that the package cache overflowed the bounds of its allocated memory

High-Water Mark

Largest size reached by the package cache