Changes to SQL Server 2012 Execution Plans

I’ve been working with execution plans quite a lot in SQL Server 2012. There are a number of changes, most of them associated with new or different functionality. I had not noticed anything really fundamental until recently. I’ve become a huge proponent of always checking the properties of the SELECT statement. There’s so much useful information in there about what’s happened with the plan generation in the optimizer (not low level stuff, but the big picture items) that you should always be checking it first as a fundamental part of your plan examinations.

Free ebook: SQL Server Execution Plans

This free book is brought to you by Red Gate Software and Simple Talk Publishing. Why my query is running slow? Why isn't my index getting used? In order to answer these questions, you have to ask the same return question in each case: have you looked at the execution plan? Grant Fritchey provides the only dedicated and detailed guide to this essential topic.

ShowPlan Operator of the Week - Split, Sort, Collapse

'Split, Sort & Collapse' is, happily, not a description of the intrepid Fabiano Amorim after his epic series of articles about the ShowPlan operators. With renewed stamina, Fabiano continues his mission to describe all the major operators by explaining the Trivial Plan and the power of unique indices.

ShowPlan Operator of the Week - Merge Join

Did you ever wonder how and why your indexes affect the performances of joins? Once you've read Fabiano Amorim's unforgettable explanation, you'll learn to love the MERGE operator, and plan your indexes so as to allow the Query Optimiser to use it.

Physical Join Operators in SQL Server - Hash Operator

In the concluding part of the Physical Operators series we look at the Hash operator.

Physical Join Operators in SQL Server - Merge Operator

Part II of the Physical Joins series looks at the Merge operator.

Operator of the Week - Lazy Spool

Continuing to illuminate the depths of SQL Server's Query Optimizer, Fabiano shines a light on the sixth major Showplan Operator on his list: the Lazy Spool. What does the Lazy Spool do that's so special, how does the Query Optimizer use it, and why is it so Lazy? Fabiano Amorim explains all.

Controlling Execution Plans with Hints

The Query Optimizer gets it right most of the time, but occasionally it chooses a plan that isn't the best possible. You can give the Query Optimiser a better idea by using Table, Join and Query hints. These come with a risk: Any choices you force on the Optimizer by using hints can turn out to be entirely wrong as the database changes with the addition of data over time. Grant Fritchey, in a chapter from his highly acclaimed book, explains further.

Execution Plans

Analyzing the SQL Server Plan Cache

Keeping in mind the importance of the cache mechanism, how could one get the plans and their usage statistics in SQL Server?