Changes to SQL Server 2012 Execution Plans

SQL Server 2012
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. Here’s an example from SQL Server 2008R2: You can see cool stuff like the size of the plan, the time it took to compile, the optimization level, the reason for early termination. Many of the properties on…
Read More

Rebind and Rewind in Execution Plans

TSQL
Ever looked at an execution plan? If you answered no, you can’t possibly have ever tried to tune a query, or, you’re doing it wrong. For every one else, no doubt you’ve looked at the tool tips or the property sheets of an operator and you’ve seen the Rebind & Rewind properties and wondered what the heck they mean. Me too. I learned as much as I could for the book on execution plans and I spent two pages describing it. Then, a little while ago, on the SQL Cruise, someone asked me to describe them and I was flummoxed. Specifically they said the explanation in the book was insufficiently clear, so I promised to put together a blog post on the topic, both to attempt to clarify my explanation…
Read More