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Message Posted: Mon, 21 Jun 2004 @ 07:41:09 GMT
<-- Anonymously Posted: Sunday, June 20, 2004 20:31 -->
I have been trying to performance tune a query which basically joins 3 or 4 tables and runs between 1 hour to 2 hours.
I recreated all these tables with the same data and same statistics in another database and it ran in 7 mins. Confused as to what could be wrong. My first step in to run CheckTable for all these Tables, which is in progress.
However when the original job runs I see the following figures in Session Information.
Est I/Os Actual I/Os -526221312 13786122 -81372160 17703380 -795344896 32817 -1920991232 Not recorded
How is the figure Estimated I/Os generated. Is it dependent on COLLECT STATS?
Why is this number showing as NEGATIVE? Whereas when it runs the Actual I/Os is a positive number.
Any insights much appreciated.
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