Microsoft KB Archive/923344

= FIX: A SQL Server 2000 session may be blocked for the whole time that a Snapshot Agent job runs =

Article ID: 923344

Article Last Modified on 11/2/2007

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APPLIES TO


 * Microsoft SQL Server 2000 Developer Edition
 * Microsoft SQL Server 2000 Enterprise Edition
 * Microsoft SQL Server 2000 Standard Edition
 * Microsoft SQL Server 2000 Personal Edition

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Bug #: 1114 (SQL Hotfix)



Microsoft distributes Microsoft SQL Server 2000 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 2000 fix release.



SUMMARY
This article describes the following about this hotfix release:
 * The issues that are fixed by this hotfix package
 * The prerequisites for installing the hotfix package
 * Information about whether you must restart the computer after you install the hotfix package
 * Information about whether the hotfix package is replaced by any other hotfix package
 * Information about whether you must make any registry changes
 * The files that are contained in the hotfix package



SYMPTOMS
Consider the following scenario in SQL Server 2000:
 * A database has transactional replication or snapshot replication installed.
 * The database has a Snapshot Agent job that creates a concurrent snapshot of the data.

In this scenario, the SQL Server 2000 session may be blocked for the whole time that the Snapshot Agent job runs.

If you run a SQL Profiler trace of the Snapshot Agent job, the trace shows that a query obtains a shared table lock on a table that belongs to the publication. The query that obtains the shared table lock resembles the following query:

select * from [dbo]. order by,  ASC



CAUSE
This problem occurs because of behavior that occurs when the Snapshot Agent job executes. When the Snapshot Agent job executes, articles that are defined in the publication are bulk-copied to the Snapshot folder. Instead of a row level lock or a page level lock, SQL Server may obtain a shared table lock to optimize the bulk copy process. The shared table lock is not released until the bulk-copy process is completed. When large tables are in the publication, the bulk-copy process may take a long time to finish.

This behavior may cause extended blocking of the SQL Server 2000 session. Other sessions that try to perform operations against the locked table are blocked until the shared table lock is released.



RESOLUTION
The installer does not install this hotfix correctly on x64-based systems. This installation issue occurs when the following conditions are true:
 * The system uses the Advanced Micro Devices (AMD) AMD64 processor architecture or the Intel Extended Memory 64 Technology (EM64T) processor architecture.

Note This issue does not occur on systems that use the Intel Itanium processor architecture.
 * The system is running a 64-bit version of the Microsoft Windows Server operating system.
 * The system is running a 32-bit version of SQL Server 2000.

We have corrected this installation issue in later builds of SQL Server 2000, starting with version 8.00.2244. When a customer who is running SQL Server 2000 on an x64-based system requests this hotfix, we will provide a build that includes this hotfix and that can be installed correctly on an x64-based system. The build that we provide will be version 8.00.2244 or a later version.

Hotfix information
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next SQL Server 2000 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites
You must have Microsoft SQL Server 2000 Service Pack 4 (SP4) installed to apply this hotfix.

For more information about how to obtain SQL Server 2000 Service Pack 4, click the following article number to view the article in the Microsoft Knowledge Base:

290211 How to obtain the latest SQL Server 2000 service pack

Restart information
You do not have to restart the computer after you apply this hotfix.

Registry information
You do not have to change the registry.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

Hotfix file information
This hotfix contains only those files that are required to correct the issues that this article lists. This hotfix may not contain of all the files that you must have to fully update a product to the latest build.

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

SQL Server 2000 hotfix, 32-bit


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
After you apply this hotfix, you must add the -EnablePageLockHintDuringBcpOut 1 command-line switch to the command line argument for the Snapshot Agent job. If you do not add the -EnablePageLockHintDuringBcpOut 1 switch to the command line argument for the Snapshot Agent job, this problem still occurs. The -EnablePageLockHintDuringBcpOut 1 switch adds a PageLock hint to the Snapshot Agent job query. SQL Server does not obtain a shared table lock after the PageLock hint is added to the Snapshot Agent job query.

To verify that you are experiencing the problem that is mentioned in the &quot;Symptoms&quot; section, run a SQL Profiler trace of the Snapshot Agent job.

Notes  Include the following events in the trace:  Lock:Acquired SQL:BatchCompleted

Additionally, include the following data columns in the trace:  BinaryData</li></ul> </li> Locate the following SQL:BatchCompleted events by using queries that resemble the following:

select * from [dbo]. order by,  ASC

Note In the query,  is a view that is defined in the published database.

One view should exist for each published table.</li> Review the Lock:Acquired events that come before each SQL:BatchCompleted event. Note the descriptive text for each event in SQL Profiler. Table Lock must appear when you select a Lock:Acquired event that represents an event that obtains a shared table lock.</li></ul>

For example, consider the following binary data:

0x00050A00CAEFB3780000000000000000

This is the binary data for a Lock:Acquired event that shows a table lock (0005) in database 10 (0A) on an object that has an ID of 2025058250 (00CAEFB378 byte-swapped).

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbbug kbfix kbtshoot kbhotfixserver kbqfe kbpubtypekc KB923344

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