RE: RE: Missing SQL in DBA_HIST_SQLSTAT
- From: "Allen, Brandon" <Brandon.Allen@xxxxxxxxxxx>
- To: "niall.litchfield@xxxxxxxxx" <niall.litchfield@xxxxxxxxx>, Herring Dave - dherri <Dave.Herring@xxxxxxxxxx>, ORACLE-L <oracle-l@xxxxxxxxxxxxx>
- Date: Tue, 2 Nov 2010 13:05:34 -0700
Slide 36 seems to say that AWR is the same as statspack in that it is not based
on "sampled data" like ASH - it is instead based on the delta between the data
captured at the time of two snapshots. I would argue that these snapshots do
still meet the definition of "sampled data", however I think what they're
trying to say is that it's not limited to the data sampled by ASH.
I think there may be confusion between DBA_HIST_ACTIVE_SESS_HISTORY and AWR
Snapshots. I'm not 100% sure my understanding is correct on this, but I think
that what Niall is saying is correct for DBA_HIST_ACTIVE_SESS_HISTORY - it is a
sampling of the sampling already done in ASH, however I believe the data used
for AWR "snapshots" is completely separate and works just like Statspack did,
so it can capture all SQL in the shared pool at the time of the snapshot if you
tell it to - it is not limited to just the SQL sampled by ASH.
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On
Behalf Of Niall Litchfield
Probably my chief resource is Graham Wood's "Sifting through the Ashes"
presentation from when 10g arrived.
http://www.oracle.com/technetwork/database/features/manageability/ppt-active-session-history-129612.pdf
specifically p13
________________________________
Privileged/Confidential Information may be contained in this message or
attachments hereto. Please advise immediately if you or your employer do not
consent to Internet email for messages of this kind. Opinions, conclusions and
other information in this message that do not relate to the official business
of this company shall be understood as neither given nor endorsed by it.
Other related posts:
