XADM: Slow Response When Searching on Custom Attributes

When you perform a search, either by using the Exchange Server Administrator program or by clicking Find on the Tools menu of the Address Book in Microsoft Outlook, searches against custom attributes may be very slow. These searches may be especially slow in large organizations when you search against the global address list.

This issue can occur because custom attributes are not indexed in the Exchange Server directory by default, which causes a search for custom attributes to run very slowly compared to a search against built-in searchable attributes.

To resolve this issue, index the custom attribute that you want to search against by using the Exchange Server Administrator program in raw mode:

WARNING: If you use the raw mode of the Exchange Server Administrator program (admin /r) incorrectly, serious problems may occur that may require you to reinstall Microsoft Windows NT Server, Microsoft Exchange Server, or both. Microsoft cannot guarantee that problems that result from using raw mode incorrectly can be solved. Use raw mode at your own risk.

1.	Start the Microsoft Exchange Server Administrator program in raw mode by typing the following at a command prompt: c:\exchsrvr\bin\admin /r
2.	On the View menu, click Raw Directory. This adds the Schema container in the left pane.
3.	Double-click the Schema object, and then press the F5 key to refresh the display.
4.	Find the custom attribute in the list, and then open the custom attribute's properties, either by double-clicking the attribute or by clicking the attribute and then clicking Properties on the File menu.
5.	When a message box is displayed, click Yes to view the raw properties of the object.
6.	From the Object attributes list, click the Search-Flags attribute.
7.	In the Edit value box, type a value of either 1 or 2 (as applicable), and then click Set. If you set the value to 1, the attribute is indexed, which makes the attribute more readily available to a query and therefore much faster to query against. If you set the value to 2, the attribute is indexed and made available for use in Ambiguous Name Resolution (ANR). For a detailed explanation of ANR, refer to the "More Information" section of this article.
8.	Click OK to close the properties.

The Search-Flags object attribute can be set to one of the following values:

�	0 (No index)
�	1 (Index)
�	2 (ANR and index)

Explanation of Ambiguous Name Resolution

ANR is an efficient search algorithm that is associated with Lightweight Directory Access Protocol (LDAP) clients that allows for objects to be bound without complex search filters. ANR is useful when you want to locate objects and attributes that have full names that you do not know. In this case, you can present a search for partial matches. For example, in a situation in which the requesting client knows a building name but not the associated number for the building, a client can query on just the building name. A full list of all of the buildings that have that building name are displayed, and the client can choose the appropriate building name and number at that point. For example, the client may see a list of the following buildings: Campus1, Campus2, and Campus3.

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base: