Microsoft® SQL Server 2012 Unleashed

Search Argument Problems

It is a blessing as well as the curse of SQL that there are a number of ways to write a query and get the same result set. Some queries, however, might not be as efficient as others. A good understanding of the Query Optimizer can help you avoid writing search arguments that SQL Server can’t optimize effectively. The following sections highlight some of the common “gotchas” encountered in SQL Server SARGs that can lead to poor or unexpected query performance.

Using Optimizable SARGs

As mentioned previously, in the section, “Identifying Search Arguments,” the Query Optimizer uses search arguments to help it narrow down the set of rows to evaluate. The search argument is in the form of a WHERE clause that equates a column ...