Comments on: SQL SERVER – Interesting Observation – Index on Index View Used in Similar Query

By: Nags

Nags — Mon, 18 Feb 2013 11:55:24 +0000

Hi,
It is great to know about this.

I have a questions here, if the base table already has a clustered index, then if we add a clustered index on the view how does it work.

By: Sai Reddy

Sai Reddy — Tue, 06 Nov 2012 07:06:24 +0000

Hi Pinal ,

Here main table is using index from view its fine.

but there is no change in query cost.

By: Janani

Janani — Mon, 29 Oct 2012 09:45:30 +0000

i’m sorry to say this, but this is little misleading..the query cost (relative to batch) will always add to 100%. it depends on the number of queries we have per batch..please refer his link for more clear answers. http://stackoverflow.com/questions/3191356/query-cost-relative-to-batch-is-100

By: Hossam Alfraih (@SaudiGeekNET)

Hossam Alfraih (@SaudiGeekNET) — Sun, 05 Feb 2012 08:03:38 +0000

Hi Pinal,

I believe this will only happen if you run the query on an Enterprise (or Developer) Edition.

However, for other editions .. using the NOEXPAND hint will ask the query optimizer to use the indexed view even if it is not a good idea.

Thanks for the nice post.

~ Hossam

By: SQL SERVER – Indexed Views and Restrictions – Quiz – Puzzle – 7 of 31 « SQL Server Journey with SQL Authority

Sun, 08 Jan 2012 01:30:45 +0000

[...] and Answers ISBN: 1466405643 Page#50 The Limitations of the Views – Eleven and more… Interesting Observation – Index on Index View Used in Similar Query Outer Join Not Allowed in Indexed Views – Limitation of the View 8 Cross Database Queries Not [...]

By: Madan agrawal

Madan agrawal — Fri, 16 Dec 2011 05:20:08 +0000

Hi Pinal,

I have two databases on same server(Development edition) ,One is little bit old in terms of data and another is just a replica taken few days before of production(Enterprise editon) server.

But when i excute the same query on both databases in development edition, both gives me two different execution plan.

One is using indexes created on view and another using indexes of table that has been reference by veiw.

Schema and indexes are same on both databases in developer edition server.

Can you let me know how can make use of index created on veiw other than table hint (noexpand) as same query when excuted in diffent database not use any table hint.

By: Ady

Ady — Fri, 23 Sep 2011 18:00:39 +0000

Hi Pinal,

Do you have any suggestion for creating full text catalog on data in 2 different languages.

By: vinit Kumar

vinit Kumar — Thu, 24 Mar 2011 09:32:05 +0000

Hi Mr. Pianldave,

I always read your post. This is a good post.

I am navice in sql server.

Would you please tell me is Index view stored in the database.

By: Plamen

Plamen — Tue, 07 Dec 2010 15:43:59 +0000

interesting as far as the inner workings of SQL Server, but nobody seems to be asking the obvious question – would you ever purposely design it this way? Isn’t it much cleaner and logical to create an index on the base table? One scenario I can think of is when you have a database created by a vendor that you do not want to contaminate with your own code, yet you need to improve its performance. Even then the indexed view needs to be in the same database for this to work, which is still not ideal.

By: kalpana

kalpana — Fri, 25 Jun 2010 00:20:53 +0000

This is really helpful article, Thanx

By: Shree Prakash

Shree Prakash — Tue, 30 Mar 2010 09:39:05 +0000

Very nice Analysis :)

It would be better if we get more details on SQL Server Query execution plan..

By: rahul

rahul — Thu, 11 Feb 2010 14:59:43 +0000

when i am using above script my estimated plan showing same value each time 100% why?

can you explain in detail

By: Konko74

Konko74 — Wed, 16 Dec 2009 12:30:52 +0000

I have a problem with this feature : if the view return LESS records than the table, the query return a bad result…

By: Sandeep

Sandeep — Tue, 10 Nov 2009 07:47:58 +0000

I am getting the same result, even after creating a index on view, and execute a query used in view.

By: Chris Leonard

Chris Leonard — Sat, 31 Oct 2009 20:29:38 +0000

@Chris Z: that’s correct about the schemabinding, although schemabinding is really required just to allow the view to be indexed in the first place.

@BartD: the NOEXPAND hint forces SQL Server to work with the view as a view, rather than expand it to its base definition during query normalization. The most common use of this parameter is for when the optimizer wants to service a query against an indexed view by hitting the base data instead of using the indexed view data. In this case, it’s the other way around – we want a query against a base table to use the indexed view.

In general, remember that there isn’t any huge difference physically between indexes and (clustered) tables. If the optimizer understands the data connection between one or more indexes / tables, it will use them as it deems best. In Enterprise or Developer Edition, this can be done with indexed views, which are really just another automated form of indexing data from one or more tables.

By: Chris Z

Chris Z — Tue, 27 Oct 2009 22:40:11 +0000

It occurs to me that the schemabinding requirement for indexed views might allow the sql engine to consider bound objects in developing the execution plan. Just a thought.

By: Ramesh

Ramesh — Thu, 01 Oct 2009 14:36:15 +0000

I think The view is a imaginary table. It was referring the original table records so the index also created automatically

By: Kuldip Bhatt

Kuldip Bhatt — Wed, 30 Sep 2009 05:04:50 +0000

very nice analysis.

By: Dharamvir

Dharamvir — Tue, 29 Sep 2009 12:03:39 +0000

Tried to run the same query, but I’m still getting the same cost. Could you tell me why it is so?

Working on SQL 2005 SP1

Regards

Dharamvir Singh

By: BartD

BartD — Mon, 28 Sep 2009 15:16:45 +0000

On editions lower than Enterprise, I believe you can force use of the view’s index with the NOEXPAND hint. But it won’t happen automatically.

By: chandra

chandra — Mon, 28 Sep 2009 13:58:38 +0000

irrespective of how i run the before and after query, it shows the same results. (i am not running the query for the second time to think that it might be from cache).

also, after the index on view has been created, the query we run still shows Missing index….

executed on sql 2008 sp1.

By: Deepika

Deepika — Fri, 25 Sep 2009 07:28:04 +0000

This is very helpful article,Thank you mr.Pinal Dave
I have learned SQL server’s Indexes before but not clearly,after reading your article i understood well

By: Chintak Chhapia

Chintak Chhapia — Thu, 24 Sep 2009 17:33:12 +0000

Yes, this is a great feature. But, this automatic substitution is done only in enterprise and developer edition. On rest of the editions we need to explicitly query the view to use the index view.

By: Brian Tkatch

Brian Tkatch — Thu, 24 Sep 2009 13:03:20 +0000

Thanx for this one.

Very interesting!

By: Noel

Noel — Thu, 24 Sep 2009 12:18:50 +0000

Thanks for another great post! Too bad the automatic consideration of an index on a view only happens with the Enterprise version.