Re: Poor Performance after 9i migration on Windows

Kalle" <not_at_valid.com> wrote in message
news:iznHc.20519$k4.409109_at_news1.nokia.com...
> Hi all,
>
> we have faced some problems after migrating our database from 8.1.7 to
> 9.2.0.5. Queries are much slower they were before...
>
> Are there any general tips what to check after migration, especially
> from init.ora -parameters...
>
> I am working on windows environment...
>
> All help appreciated
>
> km
>

Check if you were using rule based or cost based optimiser in 8.1.7. If CBO then try setting OPTIMIZER_FEATURES_ENABLE=8.1.7 and see if that returns performance to the app. If so then it strongly suggests that it's one of the newer optimiser features that's messing things up (I've had "fun" with bind variable peeking in the past). You'll then need to identify which feature is the problem and how to work around it - read up on execution plan stability - and remember to remove the OPTIMIZER_FEATURES_ENABLE parameter when finished.

Andy Received on Fri Jul 09 2004 - 03:17:24 CDT