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FIX: Performance degradation and memory leak in the ODBC Driver for SQL Server

Article ID: 814410 - View products that this article applies to.

SYMPTOMS

After you install SQL Server 2000 Service Pack 3 (SP3) (all editions), applications that use the Microsoft ODBC Driver for SQL Server (sqlsrv32.dll) may experience performance degradation and memory leaks. This is especially noticeable when you execute queries that return a large number of columns in the result set, or when you repeatedly execute prepared queries that have large numbers of columns.

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CAUSE

The Microsoft ODBC Driver for SQL Server that is installed by SQL Server 2000 SP3 changes how SQL Server allocates column metadata for ODBC statements. In certain cases, the driver can cause a memory leak.

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RESOLUTION

To resolve this problem, use one of the following methods:

Method 1

Install the Microsoft Data Access Components (MDAC) 2.7 Service Pack 1 Refresh on your computer. To download the MDAC 2.7 Service Pack 1 Refresh, visit the following Microsoft Web site:

http://www.microsoft.com/downloads/details.aspx?FamilyID=9ad000f2-cae7-493d-b0f3-ae36c570ade8

(http://www.microsoft.com/downloads/details.aspx?FamilyID=9ad000f2-cae7-493d-b0f3-ae36c570ade8)

Note To resolve this problem in a cluster, you must install the MDAC 2.7 Service Pack 1 Refresh or the hotfix on all the nodes that participate in the cluster.

Method 2

This issue is resolved in SQL Server 2000 Service Pack 3a (SP3a). To resolve this problem, obtain the latest service pack for SQL Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: 290211 INF: How to Obtain the Latest SQL Server 2000 Service Pack.

Method 3

Contact Product Support Services to obtain this hotfix.

Hotfix Information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:

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

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

Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language. The English version of this hotfix has the file attributes (or later) 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 tool in Control Panel.

   Date         Time   Version            Size    File name
   --------------------------------------------------------------
   10-Feb-2003  21:41  2000.81.9031.29    24,576  Odbcbcp.dll      
   10-Feb-2003  21:40  2000.81.9031.29   385,024  Sqlsrv32.dll

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STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was corrected in SQL Server 2000 Service Pack 3a. There is no workaround for this problem.

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