Reading query plans

To better understand what the query processor is doing, we need a way to look at query plans. SQL Server has several different ways of displaying a query plan; these techniques are collectively referred to as “the showplan options.”

SQL Server supports three showplan options: graphical, text, and XML. Each showplan option outputs the same query plan. The difference between these options is how the information is formatted, the level of detail included, how to read it, and how to use it.

Graphical plans

The graphical showplan option uses visually appealing icons that correspond to the iterators in the query plan. The tree structure of the query plan is clear. Arrows represent the data flow between the iterators. ToolTips provide ...

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