Re: optimizer parameters
From: ed lewis <eglewis71_at_gmail.com>
Date: Tue, 26 Apr 2011 06:05:06 -0400
Message-ID: <BACF631400AB4ACE9C3850B28C22BA5D_at_CATHY>
Hi Dave,
>
> So the plans are the same - I would let the vendor know what you found
> - especially that their recommendation did not solve the issue. I
> avoid "Big Knob" tuning on established systems as well. Unless the
> client has a way to test the system and determine if any performance
> got worse because of the changes.
>
> In the meantime anything stopping you from tracing execution (with
> WAIT info captured) on Dev and Prod to see differences in what the
> query is spending its time on?
>
> -Dave
>
> --
> Dave Mann
> www.brainio.us
> www.ba6.us - Database Stuff - http://www.ba6.us/rss.xml
> --
> http://www.freelists.org/webpage/oracle-l
>
>
Date: Tue, 26 Apr 2011 06:05:06 -0400
Message-ID: <BACF631400AB4ACE9C3850B28C22BA5D_at_CATHY>
Hi Dave,
Yes, I can trace the query in both environments, and compare the results.
I also doubt that the vendor will push to get these parameters implemented, knowing that they will be accountable. In the meantime, I plan to go forward, and handle each sql query on an individual basis.
I'm still curious though, if anyone has modified, and implemented these parameters. If you were installing a new application, would modifying these parameters be a general practice, even if it was not a vendor recommendation ?
thanks
ed
- Original Message ----- From: "David Mann" <dmann99_at_gmail.com> To: <oracle-l_at_freelists.org> Sent: Monday, April 25, 2011 11:06 AM Subject: Re: optimizer parameters
> >Stephane,
>> Thanks for you input. >> >> I did change these parameters on the session level, >>but it did not change the original plan for this >>particular query. So even making these changes, >>does not guarantee the desired or expected results. >>As been mentioned, the focus should be on the >>actual query. >> >> Also, this particular query takes 14 seconds on prod, >>but 6 seconds in dev. They both generate the same plan. >>The environments also differ in data volume and user >>activity. The vendor is questioning why the times are >>not comparable.
>
> So the plans are the same - I would let the vendor know what you found
> - especially that their recommendation did not solve the issue. I
> avoid "Big Knob" tuning on established systems as well. Unless the
> client has a way to test the system and determine if any performance
> got worse because of the changes.
>
> In the meantime anything stopping you from tracing execution (with
> WAIT info captured) on Dev and Prod to see differences in what the
> query is spending its time on?
>
> -Dave
>
> --
> Dave Mann
> www.brainio.us
> www.ba6.us - Database Stuff - http://www.ba6.us/rss.xml
> --
> http://www.freelists.org/webpage/oracle-l
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Tue Apr 26 2011 - 05:05:06 CDT