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"