Microsoft distributes Microsoft SQL Server 2008 R2 fixes as one downloadable file. Because the fixes are cumulative, each new release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2008 R2 fix release.
In Microsoft SQL Server 2008 R2, a database is marked as suspect when you try to recover the database. Additionally, the following assertion error is logged in the SQL Server 2008 R2 Errorlog file:
<Date> <Time> <SPID> SQL Server Assertion: File: <page.cpp>, line=4953 Failed Assertion = 'm_freeCnt + emptySlots * sizeof (Slot) >= spaceNeeded'. This error may be timing-related. If the error persists after rerunning the statement, use DBCC CHECKDB to check the database for structural integrity, or restart the server to ensure in-memory data structures are not corrupted.
Note When this issue occurs, you have to restore the database from a backup to recover from the issue.
This issue occurs because a page may not have sufficient space when you recover a database.
Any thread that is involved in an Online Index Rebuild operation or a Shrink Database operation can compress a new page. If the page has insufficient space, the assertion error occurs.
Cumulative update information
The fix for this issue was first released in Cumulative Update 7. For more information about how to obtain this cumulative update package for SQL Server 2008 R2, click the following article number to view the article in the Microsoft Knowledge Base:
2489376 Cumulative Update package 7 for SQL Server 2008 R2
Note Because the builds are cumulative, each new fix release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2008 R2 fix release. We recommend that you consider applying the most recent fix release that contains this hotfix. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
981356 The SQL Server 2008 R2 builds that were released after SQL Server 2008 R2 was released
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.