Re: An ancient mystery
Date: Fri, 21 Nov 2008 08:41:04 +0000
Is partitioning or another feature that implies the cost based optimiser in use?
On 11/21/08, Dennis Williams <oracledba.williams_at_gmail.com> wrote:
> The situation:
> Oracle 188.8.131.52 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
> 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
-- Sent from Google Mail for mobile | mobile.google.com Niall Litchfield Oracle DBA http://www.orawin.info -- http://www.freelists.org/webpage/oracle-lReceived on Fri Nov 21 2008 - 02:41:04 CST