Re: Problem with Query Speed on different instances - different execution plan

Marc Eggenberger wrote:
> I have 2 instances, one a productive and a test instance. Both
instances
> have the same objects (tables, views, indexes etc). Statistics have
been
> updated on both instances. The productive instance is not very busy.
I
> also tested those queries on times when there is none to maybe very
> little activity, same results.

Are you certain that you are gathering the statistics exactly the same way on the two instances? Have you verified that exporting the statistics from one system and importing them on the other system doesn't change the behavior?

What initialization parameters, if any, are different between the two systems? My guess is that your sort_area_size or hash_area_size is different on the two machines, but there are a variety of parameters that could influence the optimizer.

Justin Cave <jcave_at_ddbcinc.com>
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC Received on Thu Feb 10 2005 - 12:28:41 CST