Re: An ancient mystery
Date: Sat, 22 Nov 2008 10:56:11 +0100
Did someone perhaps turn on sql trace for the session, invalidating the plans ?
Don't remember off the top of my head if dbms_system was already there in 8i, but I'd assume there was a way of doing it ?
Stefan P Knecht
OPITZ CONSULTING Schweiz GmbH
Mobile +41-79-571 36 27
OCP 9i/10g SCSA SCNA
On Fri, Nov 21, 2008 at 4:05 AM, Dennis Williams < oracledba.williams_at_gmail.com> wrote:
> The situation:
> Oracle 220.127.116.11 database on Solaris 8 (soon to be upgraded to 10g)
> Rule-based Optimizer
> A query which has run for years using an indexed access to a very large
> table (maybe 100 million rows)
> suddenly decides to use a full-table scan, shutting down a critical
> business process.
> Then after several hours, it switches back to using the index.
> All concerned claim that nothing changed before or after.
> Needless to say the business users are nervous. They think maybe the
> database grew beyond some limit.
> Can anyone think of an explanation?
> Dennis Williams