Click here to monitor SSC
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Is it possible to create nonclustered index on columns with space and ignore the space so that it...


Is it possible to create nonclustered index on columns with space and ignore the space so that it does not do a table scan?

Author
Message
skhan-680833
skhan-680833
Grasshopper
Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)

Group: General Forum Members
Points: 24 Visits: 58
Is it possible to create nonclustered index on columns with space and ignore the space so that it does not do a table scan?

Thank You

SD Khan
SQLRNNR
SQLRNNR
SSC-Insane
SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)

Group: General Forum Members
Points: 21155 Visits: 18259
The table scan occurs if the Engine determines that a table scan will be more efficient. If you have null values or empty strings in your column, they will be included in your non-clustered index if you create it.

You should test the creation of your non-clustered index to determine if the new index will help improve performance. One of the factors to consider is column selectivity and uniqueness of the data in that column. The query that is causing the table-scan may also need to be revised.



Jason AKA CirqueDeSQLeil
I have given a name to my pain...
MCM SQL Server, MVP


SQL RNNR

Posting Performance Based Questions - Gail Shaw

GilaMonster
GilaMonster
SSC-Forever
SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)

Group: General Forum Members
Points: 47427 Visits: 44405
What precisely do you mean by "columns with space"?
Columns with lots of nulls?
Columns with lots of empty strings?
Columns that have varchar/nvarchar with leading/trailing spaces?
Something else?


Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


skhan-680833
skhan-680833
Grasshopper
Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)

Group: General Forum Members
Points: 24 Visits: 58
I am not sure what the developer is actually trying to achive so i told him to redo his query.....but is it possible to do teh create index in a way so that it ignores the blank spaces?
I think the problem is there has been new fields added and new data is coming in in the table.

Thank you
John Rowan
John Rowan
SSCarpal Tunnel
SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)SSCarpal Tunnel (4.1K reputation)

Group: General Forum Members
Points: 4074 Visits: 4515
Who designed the tables, the developer? If you post the table DDL, index definitions, sample data and your query, we can help more. Please reference this link to learn how to format your sample content:

http://www.sqlservercentral.com/articles/Best+Practices/61537/

John Rowan

======================================================
======================================================
Forum Etiquette: How to post data/code on a forum to get the best help - by Jeff Moden
GilaMonster
GilaMonster
SSC-Forever
SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)SSC-Forever (47K reputation)

Group: General Forum Members
Points: 47427 Visits: 44405
skhan-680833 (12/18/2009)
but is it possible to do teh create index in a way so that it ignores the blank spaces?


What do you mean? What blank spaces where?


Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass


Lynn Pettis
Lynn Pettis
SSC-Insane
SSC-Insane (24K reputation)SSC-Insane (24K reputation)SSC-Insane (24K reputation)SSC-Insane (24K reputation)SSC-Insane (24K reputation)SSC-Insane (24K reputation)SSC-Insane (24K reputation)SSC-Insane (24K reputation)

Group: General Forum Members
Points: 24285 Visits: 37993
GilaMonster (12/18/2009)
skhan-680833 (12/18/2009)
but is it possible to do teh create index in a way so that it ignores the blank spaces?


What do you mean? What blank spaces where?


Almost sounds like a filtered index. Unfortunately, not available in SQL Server 2005.

Cool
Lynn Pettis

For better assistance in answering your questions, click here
For tips to get better help with Performance Problems, click here
For Running Totals and its variations, click here or when working with partitioned tables
For more about Tally Tables, click here
For more about Cross Tabs and Pivots, click here and here
Managing Transaction Logs

SQL Musings from the Desert Fountain Valley SQL (My Mirror Blog)
SQLRNNR
SQLRNNR
SSC-Insane
SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)

Group: General Forum Members
Points: 21155 Visits: 18259
More information would be needed to best answer the question. As it is, we are only guessing at how best to help/answer your question.



Jason AKA CirqueDeSQLeil
I have given a name to my pain...
MCM SQL Server, MVP


SQL RNNR

Posting Performance Based Questions - Gail Shaw

skhan-680833
skhan-680833
Grasshopper
Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)Grasshopper (24 reputation)

Group: General Forum Members
Points: 24 Visits: 58
Thanks everyone. I have asked the developer to redo the query. I do not think filtered index is an option and as it is a vendor apps they build these indexes thourgh the vendor designer tools. Also I checked a few things and I think he should not put indexes on those columns and do the query in a different way. Thank you for all of your help and suggestions.

SD Khan
SQLRNNR
SQLRNNR
SSC-Insane
SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)SSC-Insane (21K reputation)

Group: General Forum Members
Points: 21155 Visits: 18259
You're welcome.



Jason AKA CirqueDeSQLeil
I have given a name to my pain...
MCM SQL Server, MVP


SQL RNNR

Posting Performance Based Questions - Gail Shaw

Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search