Introduction to query processing

The query optimization and execution process was introduced in Chapter 1, An Introduction to Query Tuning and Optimization, and will be explained in more detail throughout this chapter. However, before we get started, we’ll briefly explore the inner workings of the query optimization process, which extends both before and after the Query Optimizer itself. The diagram in Figure 3.1 shows the major phases of the query processing process, and each phase will be explained in more detail in the remaining sections of this chapter.

Figure 3.1 – The query-processing process

Parsing and binding are the first operations performed when a query is submitted to a SQL Server database engine. Parsing and binding produce a tree representation of the query, which is then sent to the Query Optimizer to perform the optimization process. At the beginning of this optimization process, this logical tree will be simplified, and the Query...