9.24 V$SESSION_OBJECT_CACHE

V$SESSION_OBJECT_CACHE displays object cache statistics for the current user session on the local server (instance).

Column Datatype Description

PINS

NUMBER

Number of object pins or look-ups in the cache

HITS

NUMBER

Number of object pins that found the object already in the cache

TRUE_HITS

NUMBER

Number of object pins that found the object already in the cache and in the desired state (thus, not requiring refresh from the database)

HIT_RATIO

NUMBER

Ratio of HITS / PINS

TRUE_HIT_RATIO

NUMBER

Ratio of TRUE_HITS/PINS

OBJECT_REFRESHES

NUMBER

Number of objects in the cache that were refreshed with a new value from the database

CACHE_REFRESHES

NUMBER

Number of times the whole cache (all objects) were refreshed

OBJECT_FLUSHES

NUMBER

Number of objects in the cache that were flushed to the database

CACHE_FLUSHES

NUMBER

Number of times the whole cache (all objects) were flushed to the database

CACHE_SHRINKS

NUMBER

Number of times the cache was shrunk to the optimal size

CACHED_OBJECTS

NUMBER

Number of objects currently cached

PINNED_OBJECTS

NUMBER

Number of objects currently pinned

CACHE_SIZE

NUMBER

Current size of the cache (in bytes)

OPTIMAL_SIZE

NUMBER

Optimal size of the cache (in bytes)

MAXIMUM_SIZE

NUMBER

Maximum size of the cache (in bytes)

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data