CREATE_SNAPSHOT ();
To alter the snapshot settings, use the MODIFY_SNAPSHOT_SETTINGS procedure. You can
modify the retention (in minutes) and the interval (in minutes) for snapshots. The following example
changes the interval to 30 minutes for the current database:
execute DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS
( interval => 30);
To drop a range of snapshots, use the DROP_SNAPSHOT_RANGE procedure, specifying the
start and end of the snapshot IDs to drop:
execute DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE
(low_snap_id => 1, high_snap_id => 10);
Managing Baselines
You can designate a set of snapshots as a baseline for the performance of the system. The baseline
data will be retained for later comparisons with snapshots. Use the CREATE_BASELINE procedure
to specify the beginning and ending snapshots for the baseline:
execute DBMS_WORKLOAD_REPOSITORY.CREATE_BASELINE
(start_snap_id => 1, end_snap_id => 10,
baseline_name => 'Monday baseline');
When you create a baseline, Oracle will assign an ID to the baseline; you can view past
baselines via the DBA_HIST_BASELINE view. The snapshots you specify for the beginning and
ending of the baseline are maintained until you drop the baseline. To drop the baseline, use the
DROP_BASELINE procedure:
execute DBMS_WORKLOAD_REPOSITORY.DROP_BASELINE
(baseline_name => 'Monday baseline', cascade => FALSE);
If you set the CASCADE parameter of the DROP_BASELINE procedure to TRUE, the related
snapshots will be dropped when the baseline is dropped.
Pages:
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464