Symptoms
Assume that you have some missing index entries in Microsoft SQL Server 2008 R2. When the number of entries reaches 500, and if these missing indexes are from queries that are compiled but not executed, SQL Server does not clean up the missing index entries until the corresponding queries are executed.
Resolution
The issue was first fixed in the following cumulative update of SQL Server.
Cumulative Update 12 for SQL Server 2008 R2 SP2 /en-us/help/2938478
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. Check out the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.