6.6 DBA_HIST_LIBRARYCACHE

DBA_HIST_LIBRARYCACHE displays historical statistics about library cache performance and activity.

This view contains snapshots of V$LIBRARYCACHE.

Column	Datatype	NULL	Description
SNAP_ID	NUMBER	NOT NULL	Unique snapshot ID
DBID	NUMBER	NOT NULL	Database ID for the snapshot
INSTANCE_NUMBER	NUMBER	NOT NULL	Instance number for the snapshot
NAMESPACE	VARCHAR2(15)	NOT NULL	Library cache namespace
GETS	NUMBER		Number of times a lock was requested for objects of the namespace
GETHITS	NUMBER		Number of times an object's handle was found in memory
PINS	NUMBER		Number of times a PIN was requested for objects of the namespace
PINHITS	NUMBER		Number of times all of the metadata pieces of the library object were found in memory
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 the 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_DBID	NUMBER		The database ID of the PDB for the sampled session
CON_ID	NUMBER		The ID of the container that CON_DBID identifies. 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

See Also:

"V$LIBRARYCACHE"