SQL Clone
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


IN Vs INNER JOIN


IN Vs INNER JOIN

Author
Message
purushottam2
purushottam2
SSC-Addicted
SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)

Group: General Forum Members
Points: 431 Visits: 101
Which one is more performance oriented query?

1. SELECT 1 FROM table1 WHERE Id IN (SELECT Id FROM table2)

2. SELECT 1 FROM table1 t1 INNER JOIN table2 t2 ON t1.Id = t2.Id
Dung Dinh
Dung Dinh
SSChasing Mays
SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)

Group: General Forum Members
Points: 621 Visits: 1233
purushottam2 (3/7/2013)
Which one is more performance oriented query?

1. SELECT 1 FROM table1 WHERE Id IN (SELECT Id FROM table2)

2. SELECT 1 FROM table1 t1 INNER JOIN table2 t2 ON t1.Id = t2.Id



It depends on
1 - If the table2 is small, you can use 1 or 2
2 - If both are big, you should use second solution and index the columns on ON clause
ChrisM@Work
ChrisM@Work
SSC-Dedicated
SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)SSC-Dedicated (39K reputation)

Group: General Forum Members
Points: 39418 Visits: 19991
purushottam2 (3/7/2013)
Which one is more performance oriented query?

1. SELECT 1 FROM table1 WHERE Id IN (SELECT Id FROM table2)

2. SELECT 1 FROM table1 t1 INNER JOIN table2 t2 ON t1.Id = t2.Id


http://sqlinthewild.co.za/index.php/2010/01/12/in-vs-inner-join/

“Write the query the simplest way. If through testing it becomes clear that the performance is inadequate, consider alternative query forms.” - Gail Shaw

For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden
Exploring Recursive CTEs by Example Dwain Camps
GilaMonster
GilaMonster
SSC Guru
SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)

Group: General Forum Members
Points: 212369 Visits: 46259
Dung Dinh (3/7/2013)
2 - If both are big, you should use second solution and index the columns on ON clause


Not true.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


purushottam2
purushottam2
SSC-Addicted
SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)SSC-Addicted (431 reputation)

Group: General Forum Members
Points: 431 Visits: 101
May i know the cause?
Kingston Dhasian
Kingston Dhasian
SSCertifiable
SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)SSCertifiable (5.8K reputation)

Group: General Forum Members
Points: 5832 Visits: 5279
purushottam2 (3/7/2013)
May i know the cause?


The cause is present in the link provided by Chris earlier in the thread and also provided below
http://sqlinthewild.co.za/index.php/2010/01/12/in-vs-inner-join/


Kingston Dhasian

How to post data/code on a forum to get the best help - Jeff Moden
http://www.sqlservercentral.com/articles/Best+Practices/61537/
Dung Dinh
Dung Dinh
SSChasing Mays
SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)SSChasing Mays (621 reputation)

Group: General Forum Members
Points: 621 Visits: 1233
GilaMonster (3/7/2013)
Dung Dinh (3/7/2013)
2 - If both are big, you should use second solution and index the columns on ON clause


Not true.

I mean that the second is preferred in this case. Of course, If we would like to be sure, we need to record performance on both of IN and INNER JOIN base on your environment.
In my case, I often select INNER JOIN as the first while working with large tables and check indexes. After that, record performance to compare.
GilaMonster
GilaMonster
SSC Guru
SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)

Group: General Forum Members
Points: 212369 Visits: 46259
Dung Dinh (3/7/2013)
GilaMonster (3/7/2013)
Dung Dinh (3/7/2013)
2 - If both are big, you should use second solution and index the columns on ON clause


Not true.

I mean that the second is preferred in this case.


The first is the preferred option in all cases, it's less work and if all you're doing is checking for existence of a row in another table then IN/EXISTS is the logical operation to use as that's exactly what it does.

Inner join checks, joins and fetches both rows, it'll cause duplicate rows if there's more than one matching row (in won't) and it's more work since it's a full join instead of a semi-join

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


Stuart Davies
Stuart Davies
SSCertifiable
SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)SSCertifiable (7.3K reputation)

Group: General Forum Members
Points: 7255 Visits: 4814
From the above (and Gails article) it looks like "in" has the advantage.

I'm not dissenting with any previous replies, but personally I would check the results before changing any production code.
Try it on a test system with the real table structure, indexes, data etc.
Compare the execution plans (actual not estimated) for your setup and see which is the most efficient.

-------------------------------Posting Data Etiquette - Jeff Moden Smart way to ask a questionThere are naive questions, tedious questions, ill-phrased questions, questions put after inadequate self-criticism. But every question is a cry to understand (the world). There is no such thing as a dumb question. ― Carl Sagan I would never join a club that would allow me as a member - Groucho Marx
GilaMonster
GilaMonster
SSC Guru
SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)SSC Guru (212K reputation)

Group: General Forum Members
Points: 212369 Visits: 46259
Stuart Davies (3/7/2013)
I'm not dissenting with any previous replies, but personally I would check the results before changing any production code.
Try it on a test system with the real table structure, indexes, data etc.
Compare the execution plans (actual not estimated) for your setup and see which is the most efficient.


Don't compare execution plans, compare performance characteristics. You can't tell from a comparison of exec plans which query absolutely will be faster, the costs are estimates, they can easily be wrong.

My general guidelines: Write the query to do just what you want in the simplest way possible, so if you're looking to see if rows match, use exists/in, if you're looking to retrieve columns from both tables, use join. Test the code. If it performs unacceptably under expected load, then go looking for tricks, alternatives and fancy methods

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search