June 30, 2014 at 9:54 pm
I have a statement like:
SELECT * FROM MyTable WHERE NOT PrimaryKey IN (SELECT Keys FROM #MyTempTable)
IN SQL 2008, this statement was running in less than one minute on a pretty large database that has been migrated to SQL 2012. Now, the statement takes nearly half an hour to execute.
Any suggestions?
July 1, 2014 at 1:43 am
Did you update statistics when you upgraded? I'm betting that you didn't. Run a manual UPDATE STATISTICS against the table(s) in question and see if the query performance improves.
Regards
Lempster
July 1, 2014 at 5:11 am
Check the execution plan for both. See what's being generated by the optimizer. That will help you understand if there is something mundane like statistics at fault, or if you're dealing with a regression.
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July 1, 2014 at 7:44 am
Did you check for blocking?? People forget that concurrent activity can stop SELECTs in their tracks for extended periods sometimes.
Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service
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