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How to compare a query to an execution plan?
Alternatively, if you just executed a query and chose to display its execution plan, move to the Execution Plan tab in the results pane. Right-click in a blank area of the execution plan and click Compare Showplan. Choose the second query plan file that you would like to compare with.
Why is my query faster the second time it runs?
1) It takes CPU time to figure out how to run a query. SQL Server uses memory to cache execution plans to save time the next time you run the query. The first time you run a query using the view, SQL Server has to ‘compile’ an execution plan to figure out the best way to run the query.
Which is the second type of execution plan?
The second type is the Actual Execution Plan, that is generated by executing the submitted query, displaying the actual steps that followed while executing the query. The Actual Execution Plans are preferred most of the time by database administrators as it shows more information about query execution statistics.
How to include execution plan in SQL Server?
Right-click on the query editor and choose the Include Actual Execution Plan option, as shown below: Type the Ctrl+M keyboard shortcut, and the Actual Execution Plan for the submitted query will be Included. In other words, the Actual Execution Plan option will be turned ON for that query, or any query executed in that window.
Why is the second query plan not suggesting an index?
If you flipped the order of t and tid in the key, I would expect the index hint to go away and the query to run faster without adding any new indexes. The most likely reason that the second query plan does not suggest an index is that the new filter on tid picks more than around 30% of all the values in the table.
How is query execution plan generated in SQL Server?
To elaborate – SQL Server generates the optimized query execution plan based on several factors like number of rows, index, stats, memory, CPU etc. and it might be useful to compare 2 query execution plans to see what actually changed.
When to use Index before or after execution plan?
Normally, we are used to test the performance of our query before and after creating any index to see what overall impact that is actually making on the performance of execution plan operators. The execution plan is now showing the index recommendation with overall impact of 72%. Therefore, I created the missing index as per recommendation: