Microsoft® SQL Server 2012 Unleashed

Join Selection

The job of the Query Optimizer is incredibly complex. The Query Optimizer can consider literally thousands of options when determining the optimal execution plan. The statistics are simply one of the tools that the Query Optimizer can use to help in the decision-making process.

In addition to examining the statistics to determine the most efficient access paths for SARGs and join clauses, the Query Optimizer must consider the optimum order in which to access the tables, the appropriate join algorithms to use, the appropriate sorting algorithms, and many other details too numerous to list here. The goal of the Query Optimizer during join selection is to determine the most efficient join strategy.

As mentioned at the beginning of ...