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Re: Query Plan Problem

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Fri, 26 Nov 1999 20:01:26 -0000
Message-ID: <943646688.20878.0.nnrp-11.9e984b29@news.demon.co.uk>

This is a bit of a problem,
It's worth bearing in mind that a very
small set would probably be adequate
for analyzing the table.

Perhaps a dbms_job every 5 minutes
to analyze on an estimate of 1,000 rows would be a better solution.

--

Jonathan Lewis
Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk

Lynux wrote in message <80f1if$oio3_at_imsp212.netvigator.com>...
>We have some problem on running query on ANALYZED tables that joins with
>a temp table. Because of the temporary usage our temp table,
>we does not do any analyze on such temp table within our program but set
>it as a cron job running on every hour.
>However, this results in variation on the corresponding query plan that
>we run the query in our program at different time. Frankly speaking, our
>program results in running very fast at one time and very slow at
>another time that depends on whether the statistics of the temp table is
>up-to-date.
>For example, at the first minute of an hour, the query seems running very
>fast by joining the temp table with another already ANALYZED tables.
>But, if data is filled into the temp table at 15 minutes later and query
>seems running very slow then because of the incorrect statistics of the
>temp table represented.
>
>For more information, our ANALYZED table contains about 10-20 millions of
>records and the temp table records size may vary from 0 to 400 thousand.
>And the fast query may need about 3 minutes to complete but the slow
>query may need 30 hours to complete.
>
>As a supporting DBA, I am looking for any better/stable solution for it.
>Would any person suggest what we can do to solve this problem?
>Thanks in advance!
Received on Fri Nov 26 1999 - 14:01:26 CST

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