Randy Sigmond
rsigmond at comcast.net
Wed Nov 14 09:55:59 CST 2007
John,
This might not be the proper format, but I have not posted in a very, very
long time and I cannot seem to find out how to post a question. So here it
goes.
I have been sitting on the wings learning from all of the emails that
receive from DBAdvisors.com and now I have a question of my own.
I am looking for some guidance on a couple of issues.
1. SQL Performance Metrics
2. SQL Run-Time Metrics
My current situation is calling for the identification and resolution to
track and increase an instance of SQL.
If you can assist I would be eternally grateful.
Randy Sigmond
Restech Online
www.restechonline.com
-----Original Message-----
From: dba-sqlserver-bounces at databaseadvisors.com
[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of jwcolby
Sent: Wednesday, November 14, 2007 8:20 AM
To: dba-sqlserver at databaseadvisors.com
Subject: Re: [dba-SQLServer] Performance of a unique index
An interesting explanation. Thanks.
John W. Colby
Colby Consulting
www.ColbyConsulting.com
-----Original Message-----
From: dba-sqlserver-bounces at databaseadvisors.com
[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of Michael
Maddison
Sent: Tuesday, November 13, 2007 7:53 PM
To: dba-sqlserver at databaseadvisors.com
Subject: Re: [dba-SQLServer] Performance of a unique index
John,
Hi John,
BOL doesn't help, mentions nothing about performance and unique indexes.
This guy says unique indexes improve performance.
http://drsql.spaces.live.com/blog/cns!80677FB08B3162E4!1187.entry
However, in general its unlikely you would be able to make all your indexes
unique ;-)
How good are you getting at reading execution plans?
cheers
Michael M
-----Original Message-----
From: dba-sqlserver-bounces at databaseadvisors.com
[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of jwcolby
Sent: Wednesday, 14 November 2007 3:12 AM
To: dba-sqlserver at databaseadvisors.com
Subject: Re: [dba-SQLServer] Performance of a unique index
> The fastest index is the clustered index.
And in fact it missed the point of my question. An index can be unique or
not unique. I am asking specifically about these two things, not anything
else. I have tables with DOZENS of indexes. There can be only one
clustered index and I don't have any on these tables or it is on the PKID
(created by SQL Server when I created the PKID field and made it the PK).
So I am really not interested in what is the FASTEST index in the universe,
simply in whether there is ANY difference in speed between a unique index
and a non unique index. IOW should I make all of my indexes UNIQUE because
they are faster, or should I make all of my indexes NON UNIQUE because they
are fastest or should I not care because they are equal speed.
John W. Colby
Colby Consulting
www.ColbyConsulting.com
-----Original Message-----
From: dba-sqlserver-bounces at databaseadvisors.com
[mailto:dba-sqlserver-bounces at databaseadvisors.com] On Behalf Of Arthur
Fuller
Sent: Tuesday, November 13, 2007 10:43 AM
To: dba-sqlserver at databaseadvisors.com
Subject: Re: [dba-SQLServer] Performance of a unique index
This is correct, and is due to the fact that creating a clustered index
physically resorts the table into the sequence specified by the key.
Although, JC, be aware that this is going to take a while, given the size of
your table.
A.
On 11/13/07, Robert L. Stewart <robert at webedb.com> wrote:
>
> The fastest index is the clustered index.
>
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