Re: Plan changed After creating profile
From: Adric Norris <landstander668_at_gmail.com>
Date: Thu, 30 Sep 2021 08:52:08 -0500
Message-ID: <CAJueESp+2CEMkad94-8tWamHfhf-OKoC0RdsA6Y-eL9xPZifVA_at_mail.gmail.com>
> Generally people seem to find SQL Plan Baslines more stable than SQL
> Profiles (but I can't quantify that, I only have anecdotal evidence) - so
> if you've generated a SQL Profile it might be a good idea to generate an
> SQL Plan Basline after running the query, accept it and fix it, then delete
> the profile.
Date: Thu, 30 Sep 2021 08:52:08 -0500
Message-ID: <CAJueESp+2CEMkad94-8tWamHfhf-OKoC0RdsA6Y-eL9xPZifVA_at_mail.gmail.com>
>
> Generally people seem to find SQL Plan Baslines more stable than SQL
> Profiles (but I can't quantify that, I only have anecdotal evidence) - so
> if you've generated a SQL Profile it might be a good idea to generate an
> SQL Plan Basline after running the query, accept it and fix it, then delete
> the profile.
I've seen multiple situations where the plan fixed by the baseline can't be reproduced (within the time constraints the optimizer is faced with) unless the profile is present and enabled. So there's a chance that the profile will have to be left in place.
-- "In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move." -Douglas Adams -- http://www.freelists.org/webpage/oracle-lReceived on Thu Sep 30 2021 - 15:52:08 CEST