Message
Jolene,
When I
first saw your posting, I considered if it was intended as
bait....;-)
You'll
have to forgive me for thinking so, as these are popular topics of
contention.
Now,
for the forthright (and hopefully bait-free) answer:
Please
define what you mean by "re-organization". If you're on at least 8i and
locally-managed tablespaces, your tables should never need to be
re-organized. Dozens or even hundreds of extents are not likely to be a
problem. The short answer: In general, don't worry about
re-organizing your tables. Use locally managed tablespaces with uniform
extent sizes. Pick a few different uniform extent sizes. When a
table really grows large, move to a tablespace with a larger uniform size.
See the "How to Stop Defragmenting and Start Living" paper, available on
MetaLink. (If you don't have MetaLink access, I think you can find it via
Google search as well.)
Full
table scans: Don't worry about which tables have full table scans going
on. Worry instead about your critical business processes, and how they are
performing. Do you see one that's not performing up to par?
Investigate that. You may (or may not) find slow performance caused by an
inappropriate full table scan. It could also be caused by inefficient
index range scan, where replacing it with a full table scan is
appropriate. But, the point is, by concentrating on the slowest of the
critical business processes, you're most likely to find yourself focusing on the
most important pieces of your system which simultaneously have the most room for
improvement.
Hope
that helps,
-Mark
Mark J.
Bobak
Oracle DBA
ProQuest Company
Ann Arbor,
MI
"Imagination
was given to man to compensate him for what he is not, and a sense of humor was
provided to console him for what he is." --Unknown
What SQL statement
do you use to identify tables that need reorganization?
How do you
identify tables that are used in full table scans? How often do you run
this query?
Thanks,
Jolene
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: Bobak, Mark
INET: Mark.Bobak_at_il.proquest.com
Fat City Network Services -- 858-538-5051 http://www.fatcity.com
San Diego, California -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
Received on Wed Jan 07 2004 - 13:59:34 CST
