Comments on: SQL SERVER – Guest Post by Sandip Pani – SQL Server Statistics Name and Index Creation

By: Chitra

Chitra — Mon, 14 Jan 2013 13:00:43 +0000

I find this very useful in understanding about statistics

By: DeepakM

DeepakM — Fri, 02 Nov 2012 09:36:39 +0000

Good point! It’s easy to miss this check while creating indexes.

By: shiva

shiva — Tue, 30 Oct 2012 12:11:37 +0000

very useful:) Thanks

By: Suzanne

Suzanne — Mon, 29 Oct 2012 13:55:24 +0000

Very useful!

By: Mahesh Babu

Mahesh Babu — Wed, 26 Sep 2012 07:55:28 +0000

Once we drop the index, its stats also get dropped automatically which was created with the same name as index. So i think we dont need to drop stats
manually.

By: lohithkschalam

lohithkschalam — Mon, 17 Sep 2012 14:53:11 +0000

Real good post……………..

By: Tarun Sharma

Tarun Sharma — Mon, 17 Sep 2012 13:56:02 +0000

Indeed Insightful.

By: pinaldave

pinaldave — Mon, 17 Sep 2012 08:08:17 +0000

Done and modified the code as per your request.

By: pinaldave

pinaldave — Mon, 17 Sep 2012 08:07:59 +0000

Excellent point Aasim!

By: aasim abdullah

aasim abdullah — Mon, 17 Sep 2012 07:37:55 +0000

Pinal, Please remove “SELECT 1″

that was add to test code

By: aasim abdullah

aasim abdullah — Mon, 17 Sep 2012 06:57:20 +0000

SQL Server keeps track of user created statistics through a bit in sys.stats i.e. user_created. That’s why while creating a new index, to avoid this error, we must add following IF EXISTS() code, before actual index creation code.

IF EXISTS ( SELECT *
FROM sys.indexes
WHERE name = N’IX_TestTable_1′
AND object_id = OBJECT_ID(N’[dbo].[TestTable]‘) )
DROP INDEX [dbo].[TestTable].[IX_TestTable_1]
GO
IF EXISTS ( SELECT *
FROM sys.stats
WHERE name = N’IX_TestTable_1′
AND object_id = OBJECT_ID(N’[dbo].[TestTable]‘)
AND user_created = 1 )
DROP STATISTICS [dbo].[TestTable].[IX_TestTable_1]
GO

CREATE NONCLUSTERED INDEX IX_TestTable_1 ON TestTable(Col1)

One must keep in mind that, only user created stats can be dropped, so if we just check existence of stats through name, it will return TRUE, but when it will try to drop that statistics, it will give following error.
Cannot DROP the index ‘[dbo].[TestTable].[IX_TestTable_1]‘ because it is not a statistics collection.

By: Rainmaker

Rainmaker — Mon, 17 Sep 2012 05:28:34 +0000

I think we should not only build statistics.

By: yangamuniprasad

yangamuniprasad — Mon, 17 Sep 2012 02:48:26 +0000

Excellent article by Sandip Pani. thanks pinal for sharing such an article to public..

I appreciate your efforts and keep posting like these guest articles and encouraging the hidden talents of many people.

Thanks,
Prasad