Re: AWR report ... what does W/A MB processed represent?

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Tue, 26 Mar 2013 17:42:42 -0000
Message-ID: <E6989C413FE640F7AB57B1400891378E_at_Primary>


I believe it's the change in the "bytes processed" statistics from v$pgastat;
I ran up a quick check to test that, and it seems to be true; however, as so often happens when you look too closely the "bytes" processed is a little bizarre.
I sorted 44,000 rows of data in memory, and got a report that I had needed about 7MB of memory to complete the sort (v$sql_plan_statistics_all and 10032 trace).
The "bytes processed" figure changed by 14MB - it looks like Oracle "count them out, then counts them all back in" when it's reporting bytes processed.
I didn't try to find out what happened if it did a multipass spill to disc.

The parse count may simply be a change in accounting - I think I've got a note somewhere that parse calls that became session cursor cache hits no longer get recorded under the parse count. (Or maybe it's some other specific case use - I can't remember the details, but I know I spotted some such anomaly).

Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com/all-postings

Author: Oracle Core (Apress 2011)
http://www.apress.com/9781430239543

  • Original Message ----- From: "John Hurley" <hurleyjohnb_at_yahoo.com> To: <oracle-l_at_freelists.org> Sent: Tuesday, March 26, 2013 4:44 PM Subject: AWR report ... what does W/A MB processed represent?

| Can anyone point to or give an explanation of what this AWR report
statistic means and/or where it comes from please?
|
| We just moved an OLTP database from 11.1 to 11.2 and my numbers in that
statistic have decreased dramatically ( down to 1 MB per second ).
|
| Parses per second also dropped dramatically.
|
| The change in the database server ( 11.2.0.3.4 from 11.1.0.7.12 ) also
has additional memory in the SGA and PGA. This change was made in conjunction with an application server upgrade ( went from 10.2.0.4 client to 11.2.0.3 client ).
|
| The changes are all extremely positive just trying to sort out why so
much better!
|
|
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|
|

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Received on Tue Mar 26 2013 - 18:42:42 CET

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