Microsoft KB Archive/940942

= FIX: Error message when you run a stored procedure that references tables after you upgrade a database from SQL Server 2000 to SQL Server 2005: &quot;A time-out occurred while waiting for buffer latch&quot; =

Article ID: 940942

Article Last Modified on 8/17/2007

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APPLIES TO


 * Microsoft SQL Server 2005 Standard Edition
 * Microsoft SQL Server 2005 Developer Edition
 * Microsoft SQL Server 2005 Enterprise Edition
 * Microsoft SQL Server 2005 Enterprise X64 Edition
 * Microsoft SQL Server 2005 Enterprise Edition for Itanium-based Systems
 * Microsoft SQL Server 2005 Standard X64 Edition
 * Microsoft SQL Server 2005 Standard Edition for Itanium-based Systems
 * Microsoft SQL Server 2005 Workgroup Edition

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Bug #: 50001629 (SQL Hotfix)



Microsoft distributes Microsoft SQL Server 2005 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 2005 fix release.



SYMPTOMS
Consider the following scenario. In a Microsoft SQL Server 2000 database, you have tables that contain columns of the text data type or of the image data type. You upgrade the database from SQL Server 2000 to SQL Server 2005. Then, you run a stored procedure that references the tables. In this scenario, a minidump file is generated. Additionally, error messages that resemble the following are logged in the SQL Server 2005 error log:

A time-out occurred while waiting for buffer latch -- type 4, bp 0000000187FEC080, page 1:6035561, stat 0xdc0010b, database id: 10, allocation unit Id: 71907262532485120, task 0x0000000003C3B6D8 : 0, waittime 300, flags 0x100000001a, owning task 0x0000000003C3B6D8. Not continuing to wait.

Using 'dbghelp.dll' version '4.0.5'

**Dump thread - spid = 1002, PSS = 0x0000000439107EB0, EC = 0x0000000439107EC0

***Stack Dump being sent to L:\MSSQL.1\MSSQL\LOG\SQLDump0002.txt

* *******************************************************************************

*

* BEGIN STACK DUMP:

*

*

* Latch timeout

*

* Input Buffer 102 bytes -

* EXEC dbo.sp_update_text_or_image @parameter='value'

*

* *******************************************************************************

* ---

* Short Stack Dump

Stack Signature for the dump is 0x0000000007066347

External dump process return code 0x20000001.



CAUSE
This issue occurs because of a buffer latch time-out. When SQL Server 2005 allocates pages for data of the text data type or of the image data type, a free page is latched first. Then, SQL Server 2005 searches for additional free pages. However, in some cases, the search for free pages may return the same page that is latched first. Therefore, SQL Server 2005 times out because SQL Server 2005 waits for itself.



RESOLUTION
The fix for this issue was first released in Cumulative Update 3. For more information about how to obtain this cumulative update package for SQL Server 2005 Service Pack 2, click the following article number to view the article in the Microsoft Knowledge Base:

939537 Cumulative update package 3 for SQL Server 2005 Service Pack 2

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 2005 fix release. Microsoft recommends 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:

937137 The SQL Server 2005 builds that were released after SQL Server 2005 Service Pack 2 was released

Microsoft SQL Server 2005 hotfixes are created for specific SQL Server service packs. You must apply a SQL Server 2005 Service Pack 2 hotfix to an installation of SQL Server 2005 Service Pack 2. By default, any hotfix that is provided in a SQL Server service pack is included in the next SQL Server service pack.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
For more information about what files are changed, and for information about any prerequisites to apply the cumulative update package that contains the hotfix that is described in this Microsoft Knowledge Base article, click the following article number to view the article in the Microsoft Knowledge Base:

939537 Cumulative update package 3 for SQL Server 2005 Service Pack 2

