Query Optimization and Execution
SQL Server Query Processor is perhaps the least visible and least well-known part of SQL Server. It does not expose a large set of the public features, and it allows very limited control in a documented and supported way. It accepts a query as input, compiles and optimizes it generating the execution plan, and executes it.
This chapter discusses the Query Life Cycle, and it provides a high-level overview of the Query Optimization process. It explains how SQL Server executes queries, discusses several commonly used operators, and, addresses query and table hints that you can use to fine-tune some aspects ...