5.38 DBA_HIST_ROWCACHE_SUMMARY

DBA_HIST_ROWCACHE_SUMMARY displays historical summary statistics for data dictionary activity.

This view contains snapshots of V$ROWCACHE.

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

PARAMETER

VARCHAR2(32)

NOT NULL

Name of the initialization parameter that determines the number of entries in the data dictionary cache

TOTAL_USAGE

NUMBER

Sum of the total number of entries in the cache

USAGE

NUMBER

Number of cache entries that contain valid data

GETS

NUMBER

Total number of requests for information on the data object

GETMISSES

NUMBER

Number of data requests resulting in cache misses

SCANS

NUMBER

Number of scan requests

SCANMISSES

NUMBER

Number of times a scan failed to find the data in the cache

SCANCOMPLETES

NUMBER

For a list of subordinate entries, the number of times the list was scanned completely

MODIFICATIONS

NUMBER

Number of inserts, updates, and deletions

FLUSHES

NUMBER

Number of times flushed to disk

DLM_REQUESTS

NUMBER

Number of DLM requests

DLM_CONFLICTS

NUMBER

Number of DLM conflicts

DLM_RELEASES

NUMBER

Number of DLM releases

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$ROWCACHE"