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

From: John Hurley <hurleyjohnb_at_yahoo.com>
Date: Tue, 26 Mar 2013 11:06:09 -0700 (PDT)
Message-ID: <1364321169.70429.YahooMailClassic_at_web181204.mail.ne1.yahoo.com>



Thanks Jonathan:

For parses if this is just some kind of change in how oracle counts statistics for the parses between 11.1 and 11.2 ( now ignoring session_cached_cursor hits ? ) the change in the values reported makes sense to me.

If that is correct then that change also changes dramatically the ratios reported immediately after ( Execute to Parse / Parse CPU to Parse Elapsed% ).

For W/A MB processed:
Starting to think that perhaps in 11.1 Oracle was not dividing the value for "bytes processed" by 1024*1024 ( was not calculating MB correctly ) in the AWR report and has now fixed the calculation?  

  • On Tue, 3/26/13, Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:

> From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
> Subject: Re: AWR report ... what does W/A MB processed represent?
> To: hurleyjohnb_at_yahoo.com, oracle-l_at_freelists.org
> Date: Tuesday, March 26, 2013, 1:42 PM
>
> 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!
> |
> |
> | --
> | http://www.freelists.org/webpage/oracle-l
> |
> |
>
>

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Received on Tue Mar 26 2013 - 19:06:09 CET

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