Microsoft KB Archive/817518

= Passing ADODB::Field object to ADO Command.CreateParameter method causes a memory leak =

Article ID: 817518

Article Last Modified on 11/15/2007

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APPLIES TO


 * Microsoft Data Access Components 2.8
 * Microsoft Data Access Components 2.7 Service Pack 1
 * Microsoft Data Access Components 2.7
 * Microsoft Data Access Components 2.6
 * Microsoft Data Access Components 2.5

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SYMPTOMS
When you pass an ActiveX Data Objects (ADO) Field object as a parameter value to the Command.CreateParameter method, a memory leak occurs. When you do this repeatedly, Performance Monitor shows a steady increase in both the private and virtual bytes.



CAUSE
This is caused by a bug in Microsoft Data Access Components (MDAC). Because of this bug, ADO does not release an internal BSTR. This causes memory to leak.



RESOLUTION
A supported hotfix is now 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. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or 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. To create a separate service request, visit the following Microsoft Web site:

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

The English version of this fix 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.

MDAC 2.7 SP1
    Date         Time   Version            Size    File name --  27-Mar-2003  22:30  2.71.9031.41      487,424  Msado15.dll

MDAC 2.8
   Date         Time   Version            Size    File name --  18-Feb-2004  13:28  2.80.1033.0       512,000  Msado15.dll

18-Feb-2004 13:28  2.80.1033.0       163,840  Msadomd.dll

18-Feb-2004 13:28  2.80.1033.0       184,320  Msadox.dll

18-Feb-2004 13:28  2.80.1033.0        53,248  Msadrh15.dll

18-Feb-2004 13:29  2000.85.1033.0     24,576  Odbcbcp.dll

18-Feb-2004 13:28  2000.85.1033.0    401,408  Sqlsrv32.dll

Note For a list of all the hotfixes available for MDAC 2.8, click the following article number to view the article in the Microsoft Knowledge Base:

839801 FIX: Hotfixes are available for MDAC 2.8



WORKAROUND
Pass the value of the Field object instead of the Field object itself.



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
Do not pass a Field object to the CreateParameter method because this slows performance.

Additional query words: ADO memory leak parameter field object

Keywords: kbhotfixserver kbqfe kbfix kbqfe KB817518

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