We've experienced an issue with SQL Server dropping proc cache out of the blue.
I'm talking 4GB down to 0 in 2 minutes. This has occurred approx once per day in the last two weeks.
It does happens at random times and does not coincide with process.
Has anyone seen this before?
So far as I'm aware the cache its only wiped if DBCC FREEPROCCACHE
is executed or SQL is restarted.
Version: Microsoft SQL Server 2005 – 9.00.4226.00 (X64) May 26 2009
14:58:11 Copyright (c) 1988-2005 Microsoft Corporation Enterprise
Edition (64-bit) on Windows NT 5.2 (Build 3790: Service Pack 2)
32GB RAM
Any help much appreciated.
We use Idera SQL Diagnostic manager.
Results:
DateTime Proc Cache Size MB
23/12/2015 19:19:00 4,165.63
23/12/2015 19:25:00 4,165.71
23/12/2015 19:32:00 4,178.93
23/12/2015 19:38:00 4,175.44
23/12/2015 19:44:00 4,176.87
23/12/2015 19:50:00 4,179.80
23/12/2015 19:57:00 207.16
23/12/2015 20:03:00 459.66
23/12/2015 20:09:00 510.48
23/12/2015 20:15:00 1,795.31
23/12/2015 20:21:00 2,830.94
23/12/2015 20:27:00 2,859.87
23/12/2015 20:34:00 2,877.93
23/12/2015 20:40:00 2,891.94
23/12/2015 20:46:00 2,908.82
23/12/2015 20:52:00 2,921.34
23/12/2015 20:58:00 2,975.92
Best Answer
One reason could be somebody changing options or running sp_configure. That would be logged in your error log.
Please read this article: Using Sp_configure To Change a Value Will Issue DBCC FREEPROCCACHE
and
The Plan Caching and Recompilation in SQL Server 2012 white paper gives some other possibilities.
Lots of these events should be in your log files.