Microsoft KB Archive/942250

= How to use distinguished fields and promoted properties in a BizTalk Server 2006 R2 project =

Article ID: 942250

Article Last Modified on 10/31/2007

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APPLIES TO


 * Microsoft BizTalk Server 2006 R2 Standard Edition
 * Microsoft BizTalk Server 2006 R2 Enterprise Edition
 * Microsoft BizTalk Server 2006 R2 Developer Edition
 * Microsoft BizTalk Server 2006 R2 Branch Edition
 * Microsoft BizTalk Server 2006 Standard Edition
 * Microsoft BizTalk Server 2006 Enterprise Edition
 * Microsoft BizTalk Server 2006 Developer Edition
 * Microsoft BizTalk Server 2004 Standard Edition
 * Microsoft BizTalk Server 2004 Enterprise Edition
 * Microsoft BizTalk Server 2004 Developer Edition
 * Microsoft BizTalk Server 2004 Partner Edition

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INTRODUCTION
When you create a Microsoft BizTalk Server 2006 R2 project in Microsoft Visual Studio, you can promote a field as both a distinguished field and a promoted property. As a best practice, you should promote a field as either a distinguished field or a promoted property. You should not promote a field as both a distinguished field and a promoted property.

This article describes some points to consider when you use distinguished fields and promoted properties.



MORE INFORMATION
When you use distinguished fields and promoted properties, consider the following points:
 * Use distinguished fields when you want to make decisions or to manipulate data in an orchestration. The pipeline disassembler will insert a Written property into the message context for items that are marked as a distinguished field.
 * Use promoted properties as criteria for message routing. However, notice that promoted properties are also available in an orchestration. The pipeline disassembler will insert a Promoted property into the message context for items that are marked as a promoted property.
 * Promoted properties are limited to 256 characters for performance reasons. For example, promoted properties are limited to 256 characters to improve performance in comparison operations and in storage operations.
 * Written properties do not have a size limit. However, large values that are written into the message context must still be processed by BizTalk Server. Therefore, performance may be affected.
 * A promoted property may not be available as a promoted property after you write a value into the message context. This situation can occur if the value that you write into the message context has the same name and namespace that was used to promote the property.
 * Properties that have a null value are not permitted in the message context. Therefore, if a null value is written into the message context, this value will be deleted.

