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How does SQL Server measure query execution time?
Probably the single most important factor when deciding which query to tune, or actively tuning a query, is how you go about measuring query execution time. SQL Server provides a number of different mechanisms (really, maybe too many) to get this done. However, all measures are not created equally.
What to do if you have 5 million records in SQL Server?
Your applications should not select 5 million records at the time. Try to split your query and get the data in smaller sets. Remove * from your query – it takes SQL server some time to resolve this. Put your data in temporary storage, try using VIEW or a temporary table for this.
How long should a query that returns 5 million records take?
Also, creating table partitions can help sometimes in cases where the data is partitioned by a condition (usually date and time). I did 5.5 million in 20 seconds. That’s taking over 100k schedules with different frequencies and forecasting them for the next 25 years.
Which is the most costly measure of query execution time?
Obviously, capturing an Actual Execution Plan is easily the most costly measure up there. However, if you’ve already paid the cost, clearly, you can just use the data within the plan to get an idea of the query execution time.
One simplistic approach to measuring the “elapsed time” between events is to just grab the current date and time. SELECT GETDATE(); SELECT /* query one */ 1 ; SELECT GETDATE(); SELECT /* query two */ 2 ; SELECT GETDATE();
What are the two types of execution plans available in SSMS?
SQL Server provides us with two main types of execution plans.
- The first type is the Estimated 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.
How to get execution time down in SSMS?
When in a Query window, go to the Query Menu item, select “query options” then select “advanced” in the “Execution” group and check the “set statistics time” / “set statistics IO” check boxes. These values will then show up in the messages area for each query without having to remember to put in the set stats on and off.
Why does SSMS run faster than SQL Server?
By default the queries executed in SSMS had ARITHABORT ON and the queries that come from application have ARITHABORT OFF. This is what caused the difference in execution time. You can check the SSMS SET options by going to Tools > Options > Query Execution > SQL Server > Advanced.
How to make query execution faster in SQL Server?
Focus on the “SQL Server Execution Times:” section. The output shows that this query executed in 19 milliseconds. Running it repeatedly showed numbers between 12 and 30 milliseconds on this laptop. With this level of precision measuring improvement will be far easier.
How to set execution time in SQL Server?
But you can get the timings set as a default for all queries showing in the “Messages” tab. When in a Query window, go to the Query Menu item, select “query options” then select “advanced” in the “Execution” group and check the “set statistics time” / “set statistics IO” check boxes.