I want to know when a sql-query was excuted in DBA_HIST_SQL_PLAN !!

Question

Hi, all.
I want to know when a sql query wqas excuted in past 3 month.
select * from DBA_HIST_SQL_PLAN
where plan_hash_value='1844343569'
is working?
The plan_hash_value is from v$sql_plan of current instance.
There ware 3times database shutdown/startup.
When a oracle instance is initiated, is the plan_hash_value of the same query changing?
Thanks in advance.

Answer 1

You can't go back 3 months unless your retention period is set to that length of time.
select retention from DBA_HIST_WR_CONTROL;
If you want to retain data for longer then you need to modify you snapshots settings, but this can impact your DB if it grows too large.
BEGIN
DBMS_WORKLOAD_REPOSITORY.MODIFY_SNAPSHOT_SETTINGS( retention => 100800);
END;
Then you could get the details out by using something like
select a.SNAP_ID, begin_interval_time, end_interval_time, SQL_ID, PLAN_HASH_VALUE,VERSION_COUNT, FETCHES_TOTAL, EXECUTIONS_DELTA , EXECUTIONS_TOTAL
from DBA_HIST_SQLSTAT a, DBA_HIST_SNAPSHOT b
where b.snap_id=a.snap_id
and b.instance_number=a.instance_number
and sql_id='&sql_id'
;