Posted by alexander.arvidsson on 07/16/07 09:00

Hello,

I'm new to this group and I sincerely hope I'm not stepping on anyones
toes or doing something the wrong way around by beginning my time here
by asking a question.

I'm a Oracle DBA from the beginning (been one since '97) and I've been
using SQL Server since 2001. Yesterday one of my customers (I'm a
consultant) showed me a problem they have, and it turns out it is the
'Sparse Extent Scenario' (see
http://sqlforums.windowsitpro.com/web/forum/messageview.aspx?catid=256&threadid=48326&enterthread=y
and scroll down to the user cmt_SQL)

The solution is hence simple; add clustered indexes to those tables
that don't have them. But, here is the actual problem:

The creators of the software that my customer uses (two different
systems) BOTH claim that using clustered indexes hampers performance,
each and every time. I can't find ANY resource on the internet that
validates this, quite the opposite. I am told that the best practices
is to always us a clustered index on a table.
Following their own guidelines, there is no clustered index in sight,
and hence some tables have a whopping 30GB(!) of unused space.

I'm looking for ammunition to use on the abovementioned developers.
I'm looking for detailed technical explanations why a clustered index
is so much better than an unclustered ditto. I suspect I would find it
in Kalen Delaney's books, but unfortunately I don't have them before
me (although I'm looking to order them). Could anyone point me to a
suitable usenet post, a web page or anything similar?

Kind regards,
Alexander

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