Posted by Erland Sommarskog on 12/05/55 11:31

ROAN (roan@autograf.pl) writes:
> And there is a problem... all indexes are the same(definition) in every
> datatabase, the difference is only in data. So i dont think there is a
> problem.
> I will be looking slow queries...
> But i still waiting for some aditional advices...

Statistics are not likely to be the same, as the databases are of different
sizes. And they can be out of date (even if SQL Server maintains statistics
automatically).

You can also be victim to fragmentation. A DBCC SHOWCONTIG on key tables
can reveals this. Reindexing will also fix statistics.

Also keep in mind that the optimizer determines the query plan from
*estimates* and estimates can be wrong for one reason or another. Sometimes
even if statistics are correct.

--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server SP3 at
http://www.microsoft.com/sql/techinfo/productdoc/2000/books.asp

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