Learn T-SQL Querying

Full optimization

This is phase two and is used for complex queries, where the plan produced by phase one is still considered more expensive than the cost of searching for more alternative plans—the timeout defined previously. All internal transformation rules are available for use at this point but scoped to the search space defined in the preparation tasks, and parallelism is also considered.

The full optimization phase can go through a comprehensive set of optimization alternatives, which can make it time-consuming, especially if a query plan was not found in any preceding phase because phase two must produce a plan.

The timeout defined in the Quick plan section is the only condition that limits searching for a good-enough plan during ...