Microsoft SQL Server 2014 Unleashed

Summary

The SQL Server Query Optimizer continues to improve and most of the time, chooses the most efficient query plan. When it doesn’t, the reason might be problems with the way the query itself is written, out-of-date or unavailable statistics, poor index design, or other common query performance problems. Still, on occasion, the Query Optimizer may make the wrong choice for an execution plan. When you suspect that the Query Optimizer is making the wrong decision, you can consider using the Query Optimizer hints and the plan guide features described in this chapter to override the Query Optimizer’s decisions. However, before arbitrarily applying these hints, you should analyze the queries fully to try to determine why the Query Optimizer ...