Execution Plans

SQL Server execution-plans-3 book cover

Free eBook: SQL Server Execution Plans, Third Edition

  • Article

If a query is performing poorly, and you can't understand why, then that query's execution plan will tell you not only what data set is coming back, but also what SQL Server did, and in what order, to get that data. It will reveal how the data was retrieved, and from which tables and indexes, what types of joins were used, at what point filtering, sorting and aggregation occurred, and a whole lot more. These details will often highlight the likely source of any problem.

2020-12-23 (first published: )

119,575 reads

Technical Article

Changes to SQL Server 2012 Execution Plans

  • Article

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.

You rated this post out of 5. Change rating

2011-12-14

6,689 reads

Technical Article

Free ebook: SQL Server Execution Plans

  • Article

This free book is brought to you by Red Gate Software and Simple Talk Publishing. Why my query is running slow? Why isn't my index getting used? In order to answer these questions, you have to ask the same return question in each case: have you looked at the execution plan? Grant Fritchey provides the only dedicated and detailed guide to this essential topic.

5 (1)

You rated this post out of 5. Change rating

2011-07-11

6,178 reads

Blogs

A Broken Copilot Query

By

I was testing the new SSMS (v22 Preview 3) with Copilot and ran into...

SQL Server Alerts

By

Don’t Let Trouble Sneak Up on You   Most SQL Servers run quietly. Until...

Prompt AI helping with Auditing

By

I had a conversation with a customer asking this question: how can I tell...

Read the latest Blogs

Forums

Create an HTML Report on the Status of SQL Server Agent Jobs

By Nisarg Upadhyay

Comments posted to this topic are about the item Create an HTML Report on...

Collation errors...what is best way to deal with it?

By water490

Hi I have a SP that occasionally get this error: Cannot resolve the collation...

Was the index created or not?

By water490

Hi everyone I am getting an error when I create the index but I...

Visit the forum

Question of the Day

Estimated Rows

I have two calls to the GENERATE_SERIES TVF in this code:

SELECT   TOP 10 gs.value
FROM     GENERATE_SERIES(1, 10) AS gs
ORDER BY NEWID ()
OPTION (RECOMPILE);
go
DECLARE @a int = 10;
SELECT   TOP (@a) gs.value
FROM     GENERATE_SERIES(1, @a) AS gs
ORDER BY NEWID ()
OPTION (RECOMPILE);
In the actual query plans, what is the estimated number of rows for each batch in SQL Server 2022?

See possible answers