DBA_HIST_ACTIVE_SESS_HISTORY should give you historical data. -- Cheers Riyaj Shamsudeen Principal DBA, Ora!nternals - http://www.orainternals.com Specialists in Performance, Recovery and EBS11i Blog: http://orainternals.wordpress.com On Wed, Mar 11, 2009 at 10:25 AM, Kenneth Naim <kennaim@xxxxxxxxx> wrote: Original message: Seem my v$active_session_history view only has data for the last two hours. Is this the default config, if so how can I change it? Thanks, Ken *From:* Riyaj Shamsudeen [mailto:riyaj.shamsudeen@xxxxxxxxx] * Sent:* Wednesday, March 11, 2009 10:48 AM* To:* kennaim@xxxxxxxxx* Cc:* oracle-l@xxxxxxxxxxxxx* Subject:* Re: Parallel Threads Hi Ken What version of Oracle ? If you have access to ASH data, v$active_session_history has three columns qc_instance_id, qc_session_id and qc_session_serial# can be used to see how many slaves were used by a query at a specific point in time. select to_char(sample_time, 'DD-MON-YYYY HH:MI:SS') tm, QC_INSTANCE_ID, QC_SESSION_ID,count(*) from v$active_session_history where QC_SESSION_ID is not null and session_id != qc_session_id group by to_char(sample_time, 'DD-MON-YYYY HH:MI:SS'),QC_SESSION_ID, QC_INSTANCE_ID order by 1 / TO_CHAR(SAMPLE_TIME,'DD-MO QC_INSTANCE_ID QC_SESSION_ID COUNT(*) -------------------------- -------------- ------------- ---------- 11-MAR-2009 02:47:34 1 1187 4 11-MAR-2009 02:47:34 1 1574 1 11-MAR-2009 02:47:35 1 1574 2 11-MAR-2009 02:47:36 1 1187 12 11-MAR-2009 02:47:37 1 1187 12 11-MAR-2009 02:47:37 1 1574 12 11-MAR-2009 02:47:40 1 1187 1 11-MAR-2009 02:47:40 1 1574 2 11-MAR-2009 02:47:42 1 1187 3 11-MAR-2009 02:47:42 1 1574 3 11-MAR-2009 02:47:43 1 1187 3 ....