Comments on: SQL SERVER – Avoid Using Function in WHERE Clause – Scan to Seek http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/ Personal Notes of Pinal Dave Sat, 25 May 2013 15:33:52 +0000 hourly 1 http://wordpress.com/ By: Nikhil http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-471540 Wed, 08 May 2013 19:27:36 +0000 http://blog.sqlauthority.com/?p=22973#comment-471540 Can you please tell me other alternate solutions instead of using functions in where clause to improve performance

]]> By: Ashish Srivastava http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-470462 Tue, 07 May 2013 06:05:48 +0000 http://blog.sqlauthority.com/?p=22973#comment-470462 Thanks Sir…
i use mostly with where clause but not understand why result set is too slow, but now i know what effects my query.

– Ashish

]]> By: Dony van Vliet http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-440302 Tue, 19 Mar 2013 17:48:08 +0000 http://blog.sqlauthority.com/?p=22973#comment-440302 Your original query does not return all future rows, but all rows from next year and beyond. If that is required you should first compute the start of next year from GETDATE() and then select rows where Date >= @StartOfNextYear. However calculating @StartOfNextYear from GETDATE() is not a trivial task.

]]> By: aryanverma http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-438325 Sat, 16 Mar 2013 10:40:42 +0000 http://blog.sqlauthority.com/?p=22973#comment-438325 any simple Definition For these so that i can make anyone easily understand these ?

]]> By: Imran Mohammed http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436840 Wed, 13 Mar 2013 21:10:11 +0000 http://blog.sqlauthority.com/?p=22973#comment-436840 @Pavan,

If you are expecting future records then the solution would be,
1. Date > yesterday and Date < tomorrow
2. Date between yesterday + 1 sec and tomorrow -1sec (Warning: between includes limits also)
3. Date = @Today

]]> By: Rajesh http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436477 Wed, 13 Mar 2013 05:25:41 +0000 http://blog.sqlauthority.com/?p=22973#comment-436477 HI,
Just to add further information This Index Seek behavior is having because we have selected the columns on which the indexes are already created .
Suppose if you select any other column in addition to the above 3 columns then the query would be INDEX SCAN .In that we should go for Included NON Clustered INDEX . In that case it would give you index seek instead of index scan.

]]> By: Sai Pavan http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436460 Wed, 13 Mar 2013 04:46:19 +0000 http://blog.sqlauthority.com/?p=22973#comment-436460 @Imran,

I agree with what you have suggested. I was looking at a generic solution for this problem. It could be today’s date or a particular date which which we want to check. The solution that you have provided works perfectly fine but the assumption is that there are no records of future date other than today.

Thanks for your reply.

Sai Pavan

]]> By: Dinkar http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436409 Wed, 13 Mar 2013 02:49:12 +0000 http://blog.sqlauthority.com/?p=22973#comment-436409 Would it be right to say them NON-SARgable predicates?

]]> By: Imran Mohammed http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436375 Wed, 13 Mar 2013 01:01:06 +0000 http://blog.sqlauthority.com/?p=22973#comment-436375 @KSP

I don’t know what is your requirement, but to make a generic statement, You cannot have variables in view, but if you have to use variables then got for “table value functions”.

~IM.

]]> By: Imran Mohammed http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436374 Wed, 13 Mar 2013 00:57:00 +0000 http://blog.sqlauthority.com/?p=22973#comment-436374 @Pavan,

Why do you have to do DATEDIFF = 0 ??

You can do, where Datecolumn > yesterday (greater than yesterday, which means today). Let me know if you need more help.

~ IM.

]]> By: Flávio Oliveira http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436373 Wed, 13 Mar 2013 00:54:30 +0000 http://blog.sqlauthority.com/?p=22973#comment-436373 Great post.

]]> By: KSP http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-436069 Tue, 12 Mar 2013 12:50:50 +0000 http://blog.sqlauthority.com/?p=22973#comment-436069 Hi,

How do you implement the same in Views?

Can we use variables in Views?

]]> By: Gatej Alexandru http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-435990 Tue, 12 Mar 2013 10:08:14 +0000 http://blog.sqlauthority.com/?p=22973#comment-435990 Hello,

I don’t know how many of you know that this start to happend with SQL 2005 when they change something in the “frunction evaluation mechanism”, Before that you can use function in the where clause without any performance problem.

]]> By: sqlguru http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-435917 Tue, 12 Mar 2013 08:06:42 +0000 http://blog.sqlauthority.com/?p=22973#comment-435917 Leaving getdate() in the where clause causes a call to the function for every row. For better performance, declare a local variable above the select statement and set it to getdate(), then use that variable in the where clause.

declare @theDate datetime
set @theDate = getdate()

]]> By: Sai Pavan http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-435813 Tue, 12 Mar 2013 05:14:31 +0000 http://blog.sqlauthority.com/?p=22973#comment-435813 Sir,

I am usually into situations where I have to retrieve rows from a table which are inserted on that day. For that I use DATEDIFF function with equal to 0 between date column and GETDATE(). I cannot use equal to with GETDATE() because I want on that day and not at that moment. I am not able to figure out a way to both improve performance by not using DATEDIFF while achieving the result that I need.

Thanks,
Sai Pavan

]]> By: mlatab http://blog.sqlauthority.com/2013/03/12/sql-server-avoid-using-function-in-where-clause-scan-to-seek/#comment-435790 Tue, 12 Mar 2013 03:49:16 +0000 http://blog.sqlauthority.com/?p=22973#comment-435790 thanks for the Excellent, simple and systematic article with a lot of clarity.

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