The new Analytic functions in SQL Server 2012

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The new Analytic functions in SQL Server 2012

WayneS

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January 18, 2012 at 10:08 pm

#249841

Comments posted to this topic are about the item The new Analytic functions in SQL Server 2012
Wayne
Microsoft Certified Master: SQL Server 2008
Author - SQL Server T-SQL Recipes
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BOR15K SSCertifiable Points: 5894 More actions · Answer 1

Finally they will have what Oracle had delivered ages ago....

ETL_Guy SSC Journeyman Points: 81 More actions · Answer 2

I finally see SQL Server catching up, I am so used to of Lead/Lag in DB2. It will make my life little easier. Thanks

Christian Buettner-167247 SSChampion Points: 13729 More actions · Answer 3

WayneS (1/18/2012)
Comments posted to this topic are about the item <A HREF="/articles/SQL+Server+2012/76704/">The new Analytic functions in SQL Server 2012</A>

Great information, thanks for that.

To me it was not clear immediately, what the difference between the MAX Aggregate Window Function and LAST_VALUE(X) was. In the end MAX(x) OVER (PARTITION BY y) should return the same as FIRST_VALUE(X) OVER (PARTITION BY Y, ORDER BY X DESC)

But obviously, the MAX / MIN Aggregate Window Functions do not allow you to order your partition by a different column before applying the aggregate. (And it actually does not really make sense to impose a different order on MAX or MIN.)

So the whole point of FIRST_VALUE and LAST_VALUE seem to be:

FIRST_VALUE(X) OVER (PARTITION BY Y, ORDER BY SomeOtherColumn DESC)

Any other points I may have missed?

Best Regards,

Chris Büttner

RichB SSCrazy Eights Points: 9651 More actions · Answer 4

Any idea what the performance of these things is like?

SQLRNNR SSC Guru Points: 281334 More actions · Answer 5

Good Stuff Wayne

Jason...AKA CirqueDeSQLeil
_______________________________________________
I have given a name to my pain...MCM SQL Server, MVP
SQL RNNR
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Geoff A SSChampion Points: 11511 More actions · Answer 6

Great article Wayne. This is great info to have when management wants to know why we are always upgrading 😀

stephen99999 Ten Centuries Points: 1197 More actions · Answer 7

PERCENTILE_CONT / PERCENTILE_DISC

Lets recall from statistics that continuous variables (PERCENTILE_CONT) are those that "cannot not be exactly counted," while discrete variables (PERCENTILE_DISC) "have an exact amount."

PERCENTILE_CONT would be better used when performing estimation or predictive calculations, as you are trying to determine a value from a sample of data (where the entire data set is unknown).

PERCENTILE_DISC would be better for when we need an exact measure, and the entire data set is known.

**Note: I am not a statistician, nor an analytics guru, so hopefully someone with greater experience could shine some better light on this, or at least validate my statement.

Hopefully this helps some trying to understand the purposes behind these functions.

Stephen

Jack Corbett SSC Guru Points: 184394 More actions · Answer 8

Good article Wayne. One thing I like to see in articles like this though is how you might solve the same problem without using the new functions. Just to see how much the new functions help.

Jack Corbett
Consultant - Straight Path Solutions
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mtillman-921105 SSCertifiable Points: 7156 More actions · Answer 9

Thank you for this Wayne - I'll definitely come back to it later. I like your concise writing style with helpful examples too.

- Mark

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge. - Stephen Hawking

j-1064772 SSCertifiable Points: 5316 More actions · Answer 10

How do the newfangled Analytics functions compare with the Quirky Update method used for - among other things - creating running totals in term of performance ?

tim.hulse SSC Veteran Points: 258 More actions · Answer 11

tim.hulse

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Points: 258

January 19, 2012 at 1:23 pm

#1436148

Thanks - this is a great summary.

Ken SSCoach Points: 17191 More actions · Answer 12

Nice article, very helpful. It's nice to see articles like this with examples. Definitely helps to prove to others why upgrades are needed. 🙂

WayneS SSC Guru Points: 95460 More actions · Answer 13

Christian Buettner-167247 (1/19/2012)
WayneS (1/18/2012)
Comments posted to this topic are about the item <A HREF="/articles/SQL+Server+2012/76704/">The new Analytic functions in SQL Server 2012</A>
Great information, thanks for that.
To me it was not clear immediately, what the difference between the MAX Aggregate Window Function and LAST_VALUE(X) was. In the end MAX(x) OVER (PARTITION BY y) should return the same as FIRST_VALUE(X) OVER (PARTITION BY Y, ORDER BY X DESC)
But obviously, the MAX / MIN Aggregate Window Functions do not allow you to order your partition by a different column before applying the aggregate. (And it actually does not really make sense to impose a different order on MAX or MIN.)
So the whole point of FIRST_VALUE and LAST_VALUE seem to be:
FIRST_VALUE(X) OVER (PARTITION BY Y, ORDER BY SomeOtherColumn DESC)
Any other points I may have missed?

Actually...

this article only talks about the Analytic functions. You might want to look at my previous article The OVER Clause enhancements in SQL Server code named “Denali”, CTP3[/url].

Basically, the MIN/MAX functions DO allow you to order your partition by a different column. But let's talk about this "over there"... it's more appropriate there.

Wayne
Microsoft Certified Master: SQL Server 2008
Author - SQL Server T-SQL Recipes

If you can't explain to another person how the code that you're copying from the internet works, then DON'T USE IT on a production system! After all, you will be the one supporting it!

Links:
For better assistance in answering your questions
Performance Problems
Common date/time routines
Understanding and Using APPLY Part 1 & Part 2

WayneS SSC Guru Points: 95460 More actions · Answer 14

RichB (1/19/2012)
Any idea what the performance of these things is like?

Did you click on that "TSQL Challenges Winner" icon in my signature? (Well, that is using the aggregate functions and not the analytic, but I believe them to be similar.)

Wayne
Microsoft Certified Master: SQL Server 2008
Author - SQL Server T-SQL Recipes

If you can't explain to another person how the code that you're copying from the internet works, then DON'T USE IT on a production system! After all, you will be the one supporting it!

Links:
For better assistance in answering your questions
Performance Problems
Common date/time routines
Understanding and Using APPLY Part 1 & Part 2