Index question

Does the performance increase if the same index created on
the table twice ?. Say I have a 2 nonclustered index on
the same column. Does it increase the performance or the
performance will be the same if there is only 1 index on
that column ?
Thanks.
The engine can only use one index, so no. In fact, I would bet this would
be worse off for your system... first, the engine has to consider another
option when creating a query plan, plus the extra space the additional index
will require.
Why do you think this would be better?
Aaron Bertrand
SQL Server MVP
http://www.aspfaq.com/
"Jim" <anonymous@.discussions.microsoft.com> wrote in message
news:eb3a01c43cef$a527b630$a301280a@.phx.gbl...
> Does the performance increase if the same index created on
> the table twice ?. Say I have a 2 nonclustered index on
> the same column. Does it increase the performance or the
> performance will be the same if there is only 1 index on
> that column ?
> Thanks.
|||I never thought it would be better. Our dumb developers
created a couple of indexes like that in the production
database and I removed the duplicates thinking it wouldn't
cause performance issues............
Thanks.........

>--Original Message--
>The engine can only use one index, so no. In fact, I
would bet this would
>be worse off for your system... first, the engine has to
consider another
>option when creating a query plan, plus the extra space
the additional index
>will require.
>Why do you think this would be better?
>--
>Aaron Bertrand
>SQL Server MVP
>http://www.aspfaq.com/
>
>
>"Jim" <anonymous@.discussions.microsoft.com> wrote in
message[vbcol=seagreen]
>news:eb3a01c43cef$a527b630$a301280a@.phx.gbl...
on
>
>.
>
|||Yes bad practise - no reason for it and like Aaron said, there's the disk space too. Also, when you modify the data you have to change the data in the table and the two indexes. You should get your developers to script their indexes (and make sure they na
me them!)
Alicia
Http://www.sqlporn.co.uk