dbasql79 (12/27/2012)
Check Sql Error log to find what cleared your plan cache.There you can see some error messages like below.QL Server has encountered 1 occurrence(s) of cachestore flush for the 'Object Plans' cachestore (part of plan cache) due to "" Operation.
That only logs complete clearing of the cache, not if single plans are aged out or invalidated.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability