Active Directory, Second Edition

Optimizing Searches

Whether you are searching Active Directory using filters or with SQL, there are some important guidelines to follow that can help reduce load on the domain controllers, increase performance of your scripts and applications, and reduce the amount of traffic generated on the network. It is also important to socialize these concepts with others as much as possible. It takes only a couple of badly written search filters in a heavily used application to severely impact the performance of your domain controllers!

Efficient Searching

Understanding how to write efficient search criteria is the first important step to optimizing searches. By understanding a few key points, you can greatly improve the performance of your searches. It is also important to reuse data retrieved from searches or connections to Active Directory as much as possible. The following list describes several key points to remember about searching:

• Use at least one indexed attribute per search. Certain attributes are marked as “indexed” in Active Directory, which allows for fast pattern matching. They are typically single-valued and unique, which means searches using indexed attributes can determine which objects match them very quickly. If you don’t use indexed attributes, the database equivalent of a full table scan must be done to determine the matches.

• Use a combination of objectclass and objectcategory in every search. While most of the queries used so far in this chapter have used only objectclass ...