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Re: DB File Sequential Read Waits

From: Joel Garry <joel-garry_at_home.com>
Date: 6 Jan 2004 16:52:24 -0800
Message-ID: <91884734.0401061652.30accfbe@posting.google.com>


pharfromhome_at_hotmail.com (Geomancer) wrote in message news:<cf90fb89.0401040937.52d574e9_at_posting.google.com>...
> There are three things I can think of that might help:
>
> a) Find queries where the number of disk reads is
> significantly higher than the number of rows returned,
> and check to see if the tkprof output shows the table
> returning far fewer rows than the index, where the
> disk figure in the tkprof output is roughly the same as
> the INDEX line rows. This indicates lots of table blocks
> being visited unnecessarily, and MIGHT be fixed by adding
> columns to indexes to avoid the excess table visits.
>
> Jonathan,
>
> You mention checking disk reads.
>
> Do you subscribe to the notion that one should only tune to reduce logical I/O?

Register at and read
http://www.hotsos.com/downloads/registered/00000006.pdf so you don't get people jumping on you.

jg

--
@home.com is bogus.
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Received on Tue Jan 06 2004 - 18:52:24 CST

Original text of this message

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