Comments on: SQL SERVER – Difference Between Index Scan and Index Seek

By: Kuldip Bhatt

Kuldip Bhatt — Sun, 25 Dec 2011 14:06:32 +0000

thanks very nice sir

By: 1111ali

1111ali — Tue, 11 Oct 2011 19:09:06 +0000

It is really a usefull information for DBA while reading exec. plan

By: Just

Just — Mon, 19 Sep 2011 13:34:07 +0000

nice a lot!!!

By: Paras Rangraj

Paras Rangraj — Wed, 20 Apr 2011 04:42:43 +0000

Hi,
I have six table in my query and while looking at the execution plan i found that one of my table is showing Index scan without any kind of predicates. Please let me know whether this query is good or should i optimise this query.

By: Azhar Iqbal

Azhar Iqbal — Fri, 21 Jan 2011 10:00:19 +0000

Hi,
Your articles differs in difficulty levels. As You have readers from all levels of intelligence.
So please carry on these types of articles b/c these are very helpful for normal readers.
Thanks
Azhar

By: Girish Rokade

Girish Rokade — Thu, 30 Dec 2010 08:30:20 +0000

Hi,
Can you tell that which data structures actually columns uses to store the data which has some indexes applied?

By: abhishek

abhishek — Mon, 22 Nov 2010 13:35:19 +0000

Hi Pinal,
I have a simple question, Does the columns used in SELECT clause affect the index usage? e.g. in the scenario (given in article) if we write follwing queries:
SELECT col4, col5 FROM table1 where col1 = ‘abc’ and col3 = ‘xyz’

SELECT col1, col3 FROM table1 where col1 = ‘abc’ and col3 = ‘xyz’

SELECT col1, col4 FROM table1 where col1 = ‘abc’ and col3 = ‘xyz’

As indexes are on col1 and col3, how these queries will behave in terms of index utilization??

By: latha

latha — Thu, 28 Oct 2010 09:17:38 +0000

hai

to improve the performance i partition my table based on a column.but when updating it gives an error

By: shrikrishna

shrikrishna — Wed, 15 Sep 2010 15:17:48 +0000

Hi Ashish

According my knowlegde Sequence is index seek,index scan,table seek and table scan.

By: N R

N R — Tue, 27 Jul 2010 11:18:48 +0000

how to separate date and time

By: Brian Savoie

Brian Savoie — Thu, 24 Dec 2009 21:42:41 +0000

Whether we like this kind of article or not is irrelevant. Anyone who wants to write efficient queries better understand it; which is why I’m trying to! This is the least enjoyable part of writing queries, but the most rewarding and necessary.

I Appreciate this resource, thank you!!

By: Gaurav Pratap

Gaurav Pratap — Mon, 09 Nov 2009 08:23:18 +0000

Agree with all, this give us an insight of functionoing of SQL server.

More such work appreciated.

By: Wayne E. Pfeffer

Wayne E. Pfeffer — Mon, 19 Oct 2009 19:21:47 +0000

I too am interested in more articles like this, especially about indexes.

By: Sonal

Sonal — Tue, 25 Aug 2009 09:40:02 +0000

This article is really useful , and example is very nice to understand. I am looking for this type of example.
Can u provide this type of article regrading INDEX rebuild and reorganize.Thanks a lot.

By: Suresh Kurapati

Suresh Kurapati — Thu, 02 Jul 2009 15:31:50 +0000

Pinal

Thanks for short , simple yet effective information on index scans and seeks. Of course, I (and I am sure all others readers also) will truly appreciate if you can expand more on this subject

By: purushotam Bhardwaj

purushotam Bhardwaj — Sat, 20 Jun 2009 07:34:31 +0000

I want more example for index scan and index seek

By: Abhilash

Abhilash — Thu, 18 Jun 2009 10:01:22 +0000

As you guessed I’s looking for this kind of articles.
Thanks.

By: Jose Mariano Alvarez

Jose Mariano Alvarez — Tue, 24 Feb 2009 03:19:46 +0000

Interesting article. I prefer to say (when related to predicates), that “Indexseek” is used by engine when a very low percentage of rows of table satisfy the predicate.

By: Dhawal

Dhawal — Thu, 05 Feb 2009 18:24:38 +0000

Such articles are indeed interesting …. Would definately like to see more…. Thanks Pinal.

By: Meysam

Meysam — Mon, 26 Jan 2009 06:55:30 +0000

I really like this kind of articles.

Just one question. I’ve heard that any kind of scan is bad, no matter if it’s a table or index scan. Sometimes in my queries I see an Index Scan, but I can not turn it into an Index Seek even if by changing or reordering index columns. Please explain the reason and tell us the ways to get rid of Index Scans.

Thanks

By: jaydee

jaydee — Sat, 24 Jan 2009 17:17:15 +0000

hi pinal,
I have a question, Can i create the dynamic indexes on the predicates that i am using in the query of a sp and drop it right after executing the query. Is it the right way to create and drop indexes so that the optimizer uses the correct index and Index seek will not arise.

By: rajeev

rajeev — Thu, 22 Jan 2009 03:56:32 +0000

Hi pinal

Thanks for a very good article in index
rajeev

By: dinesh

dinesh — Thu, 22 Jan 2009 03:36:07 +0000

I like this kind of articles, this is really good n i can understand the depth of the sql server how it works

Thanks
Dins!

By: Ganesh

Ganesh — Wed, 21 Jan 2009 18:00:08 +0000

Understanding how the sql server basically work or reacts to the query is very important. Help us to understand the internals by writing more on this

Thanks
Ganesh

By: Ashish Jain

Ashish Jain — Wed, 21 Jan 2009 05:19:48 +0000

Hi Pinal,

Thanks for a very good article on index.

I want to know what is difference between INDESX SCAN, INDESX SEEK, TABLE SCAN and TABLE SEEK…And what will be the preference order in term of optimization.

Ashish