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FIX: The performance of a .NET Framework 4-based WCF service becomes poor when the deserialization of large datasets occurs

Consider the following scenario:
  • You have a Microsoft .NET Framework 4-based Windows Communication Foundation (WCF) service that uses a dataset as a parameter.
  • The dataset contains very long strings.

In this scenario, the performance of the WCF service becomes poor when the deserialization of large datasets occurs. Both the memory usage and CPU usage are high, and the call to the WCF service takes a long time to finish. If you profile the WCF service, you notice that garbage collection frequently occurs.
This problem occurs because of an issue in the System.Data.dll assembly.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

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, contact 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 website: 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.


You must have the .NET Framework 4 installed to apply this hotfix rollup.

Restart information

You may have to restart the computer after you install this hotfix if the affected file is being used. We recommend that you to close all .NET Framework applications before you install this hotfix.

File information

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.

For all supported x86-based versions of Windows XP, of Windows Server 2003, of Windows Vista, of Windows Server 2008, and of Windows 7
File nameFile versionFile sizeDateTimePlatform,000,15201-Jul- 201108:02x86
For all supported x64-based versions of Windows XP, of Windows Server 2003, of Windows Vista, of Windows Server 2008, of Windows 7, and of Windows Server 2008 R2
File nameFile versionFile sizeDateTimePlatform,142,48801-Jul- 201108:46x64
For all supported IA-64-based versions of Windows Server 2003, of Windows Server 2008, and of Windows Server 2008 R2
File nameFile versionFile sizeDateTimePlatform,320,15201-Jul- 201109:32IA-64
Note Because of file dependencies, the most recent fix that contains these files may also contain additional files.

To work around this problem, avoid using a long string in a dataset when the dataset has to be passed as a parameter to a WCF service.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

Article ID: 2565600 - Last Review: 08/01/2011 18:12:00 - Revision: 1.0

Microsoft .NET Framework 4

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