Re: Why "Separating Data and Indexes improves performance" is a m yth?

From: Tim Gorman <tim_at_sagelogix.com>
Date: Fri, 23 Apr 2004 12:06:31 -0600
Message-ID: <BCAEB747.13BBA%tim@sagelogix.com>

Do you see a lot of FAST FULL scans? Generally, when I see them, they are the result of either:

SELECT COUNT(*) on table with PK (usually ad-hoc, thus rare)
result of index being forced into usage due to an inappropriate INDEX hint (i.e. no predicates using the index in the WHERE clause)
ALTER INDEX ... REBUILD (hopefully relatively rare)

When do you see them? Granted, you might want to live in my world (an elevated part of the US called Colorado), but I didn't want to assume that that is what you meant... :-)

on 4/23/04 11:20 AM, Jesse, Rich at Rich.Jesse_at_quadtechworld.com wrote:

> Man, I wish I lived in your world...
>
> Rich
>
> Rich Jesse System/Database Administrator
> rich.jesse_at_quadtechworld.com QuadTech, Sussex, WI USA
>
>

>> From: Tim Gorman
>> Sent: Friday, April 23, 2004 12:15 PM
>> 
>> The other two methods, FULL SCAN and FAST FULL SCAN, are not
>> often used
>> during queries, but are most often used during ALTER INDEX
>> ... REBUILD or
>> when index usage is explicitly hinted but not really
>> appropriate.


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Received on Fri Apr 23 2004 - 13:04:59 CDT