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Estimated Execution Plan or Actual Execution Plan?

Download PDF – Estimated Execution Plan or Actual Execution Plan?

Notes only

Let’s go through some of the differences given below-

Estimated Execution Plan Actual Execution Plan
In this case you will not observe results tab. In this case you will observe results tab.
They are good for long running queries. They are not useful if your query is taking too much of time. Although we can run our queries for hours but that will kill out your time. So it depends on you which one to choose i.e. actual or estimated. In most of the case people use estimated if the query is taking too long time.
They are created without running the queries. They are created when actual query runs.
They use statistics to get execution plan. Means they are based on statistical understanding of data. May not be correct every time. For example multi valued table variable will always give you 1 as the estimated number of rows. In 2014 they have upgraded it to 100 rows. They may produce bad plans if the statistics are not up to date. They are created using real data.

Example of Estimated Execution Plan-

Pawan Kumar Khowal - EstimatedlExecutionPlan

Example of Actual Execution Plan-

Pawan Kumar Khowal - ActualExecutionPlan

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