DBMS_WORKLOAD_REPOSITORY

The DBMS_WORKLOAD_REPOSITORY package lets you manage the Workload Repository, performing operations such as managing snapshots and baselines.

DROP_SNAPSHOT_RANGE Procedure

This procedure drops a range of snapshots.

Syntax

DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE(
   low_snap_id    IN  NUMBER,
   high_snap_id   IN  NUMBER
   dbid           IN  NUMBER DEFAULT NULL);

Parameters

Examples

This example drops the range of snapshots between snapshot id 102 to 105 for the local database:

EXECUTE DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE(102, 105);

If you query the dba_hist_snapshot view after the Drop Snapshot action, you will see that snapshots 102 to 105 are removed from the Workload Repository.

---

MODIFY_SNAPSHOT_SETTINGS Procedures

This procedure controls three aspects of snapshot generation.

• The INTERVAL setting affects how often snapshots are automatically captured.

• The RETENTION setting affects how long snapshots are retained in the Workload Repository.

• The number of SQL captured for each Top criteria. If the user manually specifies a value for Top N SQL, the AWR SQL collection will use the user-specified number for both automatic and manual snapshots.

There are two overloads. The first takes a NUMBER and the second takes a VARCHAR2 for the topnsql argument. The differences are described under the Parameters description.

Syntax

DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(
   retention   IN  NUMBER    DEFAULT NULL,
   interval    IN  NUMBER    DEFAULT NULL,
   topnsql     IN  NUMBER    DEFAULT NULL,
   dbid        IN  NUMBER    DEFAULT NULL);

DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(
   retention   IN  NUMBER    DEFAULT NULL,
   interval    IN  NUMBER    DEFAULT NULL,
   topnsql     IN  VARCHAR2,
   dbid        IN  NUMBER    DEFAULT NULL);

Parameters

Examples

This example changes the interval setting to one hour and the retention setting to two weeks for the local database:

EXECUTE DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS(
  interval  =>  60,
  retention =>  20160);

If you query the DBA_HIST_WR_CONTROL table after this procedure is executed, you will see the changes to these settings.