8.36 V$LIBRARYCACHE

V$LIBRARYCACHE contains statistics about library cache performance and activity.

Column Datatype Description

NAMESPACE

VARCHAR2(64)

Library cache namespace

GETS

NUMBER

Number of times a lock was requested for objects of this namespace

GETHITS

NUMBER

Number of times an object's handle was found in memory

GETHITRATIO

NUMBER

Ratio of GETHITS to GETS

PINS

NUMBER

Number of times a PIN was requested for objects of this namespace

PINHITS

NUMBER

Number of times all of the metadata pieces of the library object were found in memory

PINHITRATIO

NUMBER

Ratio of PINHITS to PINS

RELOADS

NUMBER

Any PIN of an object that is not the first PIN performed since the object handle was created, and which requires loading the object from disk

INVALIDATIONS

NUMBER

Total number of times objects in this namespace were marked invalid because a dependent object was modified

DLM_LOCK_REQUESTS

NUMBER

Number of GET requests lock instance locks

DLM_PIN_REQUESTS

NUMBER

Number of PIN requests lock instance locks

DLM_PIN_RELEASES

NUMBER

Number of release requests PIN instance locks

DLM_INVALIDATION_REQUESTS

NUMBER

Number of GET requests for invalidation instance locks

DLM_INVALIDATIONS

NUMBER

Number of invalidation pings received from other instances

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