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Re: full-scan vs index for "small" tables

From: Steve Perry <sperry_at_sprynet.com>
Date: Tue, 27 Jun 2006 21:46:52 -0500
Message-Id: <5E374178-90CE-4760-920C-2AE24BE7F679@sprynet.com>


On Jun 27, 2006, at 09:52 AM, Cary Millsap wrote:

"Most people guess Its got to be I/O. But it is I/O in fewer than 5% of cases Ive witnessed since about 1995"

What have been the majority of problems you've run into?

For me, IO used to be the problem ( after 2GB drives went away and before SANs showed up). Mainly because the sysadmins treated database file systems like "file servers". they'd put everything on a few spindles and fill them up. then mgt. would say the servers were under utilized if the average utilization was below 60% so they would load up the servers with applications to max out the memory. After I changed companies and started using SANs, most problems seem to be cpu bound on the server. I've seen a few really good nested loops queries on small tables that would take hours to complete.

I'm curious what others have run into.

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Received on Tue Jun 27 2006 - 21:46:52 CDT

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