Columnstore Indexes

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Columnstore Indexes

dstrickrott

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March 14, 2015 at 11:53 am

#295954

Comments posted to this topic are about the item Columnstore Indexes
March 16, 2015 at 5:03 am

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TomThomson SSC Guru Points: 104773 More actions · Answer 1

Nice simple question.

After getting the 23rd Feb question wrong because I forgot that 2012 didn't include clustered columnstore I found this one rather easy.

Tom

Hany Helmy SSChampion Points: 13921 More actions · Answer 2

Gr8 question, thanx 🙂

Did anyone tried this feature before? And is there any actual performance gained?

Thanks & Best Regards,
Hany Helmy
SQL Server Database Consultant

patricklambin SSCrazy Eights Points: 9994 More actions · Answer 3

As Tom Thomson wrote , it was easy to find the 2 good choices after the question of 02/23/2015.

Moreover , I was helped by 2 sessions about Columnstore indexes during the SQL Server days and the TechDays 2014 ( I am happy to have a good remembrance ) even if it is not one of my favorite topics.

So thanks Dawn Strickrott

Carlo Romagnano SSC-Insane Points: 22663 More actions · Answer 4

Hany Helmy (3/15/2015)
Gr8 question, thanx 🙂
Did anyone tried this feature before? And is there any actual performance gained?

I tried just a little. The answer is as usual "depends".

If you query the whole table, there's a gain.

Koen Verbeeck SSC Guru Points: 259105 More actions · Answer 5

Can only create nonclustered columnstore index in SQL Server 2012

This makes it seem like you could only create nonclustered columnstore indexes in SQL 2012, but not in 2014. At least how I interpret it 🙂

Anyway, I got it correct as only one single correct answer seemed a bit few.

Need an answer? No, you need a question
My blog at https://sqlkover.com.
MCSE Business Intelligence - Microsoft Data Platform MVP

Koen Verbeeck SSC Guru Points: 259105 More actions · Answer 6

Carlo Romagnano (3/16/2015)
Hany Helmy (3/15/2015)
Gr8 question, thanx 🙂
Did anyone tried this feature before? And is there any actual performance gained?
I tried just a little. The answer is as usual "depends".
If you query the whole table, there's a gain.

The point of columnstore indexes is that there should be a tremendous gain when you only read a few columns, because the columnstore indexes will only read those columns, while traditional row store tables/indexes have to read all rows/pages and filter the unnecessary columns out.

Need an answer? No, you need a question
My blog at https://sqlkover.com.
MCSE Business Intelligence - Microsoft Data Platform MVP

Emil B SSCertifiable Points: 5568 More actions · Answer 7

Got it right! Playing euromillion today! (I work with 2008)

webrunner SSC-Dedicated Points: 31851 More actions · Answer 8

Thanks for the question!

- webrunner

-------------------
A SQL query walks into a bar and sees two tables. He walks up to them and asks, "Can I join you?"
Ref.: http://tkyte.blogspot.com/2009/02/sql-joke.html

Jacob Wilkins One Orange Chip Points: 27976 More actions · Answer 9

Koen Verbeeck (3/16/2015)
Can only create nonclustered columnstore index in SQL Server 2012
This makes it seem like you could only create nonclustered columnstore indexes in SQL 2012, but not in 2014. At least how I interpret it 🙂

Yup, same interpretation here. I spent a few seconds trying to figure out if someone would be so tricky as to provide only one correct answer, and decided that they might.

C'est la vie.

🙂

Koen Verbeeck SSC Guru Points: 259105 More actions · Answer 10

Jacob Wilkins (3/16/2015)
Koen Verbeeck (3/16/2015)
Can only create nonclustered columnstore index in SQL Server 2012
This makes it seem like you could only create nonclustered columnstore indexes in SQL 2012, but not in 2014. At least how I interpret it 🙂
Yup, same interpretation here. I spent a few seconds trying to figure out if someone would be so tricky as to provide only one correct answer, and decided that they might.
C'est la vie.
🙂

You have no faith in people 😀

Need an answer? No, you need a question
My blog at https://sqlkover.com.
MCSE Business Intelligence - Microsoft Data Platform MVP

Raghavendra Mudugal SSChampion Points: 10658 More actions · Answer 11

..

ww; Raghu
--
The first and the hardest SQL statement I have wrote- "select * from customers" - and I was happy and felt smart.

Raghavendra Mudugal SSChampion Points: 10658 More actions · Answer 12

Koen Verbeeck (3/16/2015)
Carlo Romagnano (3/16/2015)
Hany Helmy (3/15/2015)
Gr8 question, thanx 🙂
Did anyone tried this feature before? And is there any actual performance gained?
I tried just a little. The answer is as usual "depends".
If you query the whole table, there's a gain.
The point of columnstore indexes is that there should be a tremendous gain when you only read a few columns, because the columnstore indexes will only read those columns, while traditional row store tables/indexes have to read all rows/pages and filter the unnecessary columns out.

+1

(fyi. just posted your statistical mode calculation post on linkedin, very helpful, thank for the article)

ww; Raghu
--
The first and the hardest SQL statement I have wrote- "select * from customers" - and I was happy and felt smart.