September 24, 2012 at 8:04 am
We're running SQL Server 2008 R2 and the views in question are not indexed.
Originally the SELECTs against the views ran less than a second.
But, after a period of time (about 10 days), the performance on the views degrades to 50-60 seconds.
The server is very active and the underlying tables are updated frequently;
so there is some index fragmentation during the week but we we are doing weekly reorgs,
and that doesn't look like the issue.
However, IF we just recreate the view, performance returns to the sub-second range again
- and remains there... until the next time.
Can someone explain what may be happening?
:unsure:
September 24, 2012 at 11:11 am
It sounds like you might be experiencing bad parameter sniffing... possibly. Recreating the view forces a recompile of the plan. If your statistics are aging over the week, but not enough to force a plan recompile, entirely possible, you may see the type of behavior you're seeing. Forcing a scheduled recompile on the plan is one possible solution. You could also try manually updating the statistics.
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September 24, 2012 at 11:56 am
Thanks, I'll see if I can hone in on the issue.
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