Re: Queries slower in 8.1.7.0 than in 8.1.6.2

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Fri, 1 Feb 2002 15:06:59 -0000
Message-ID: <1012575934.20905.0.nnrp-02.9e984b29@news.demon.co.uk>

If the databases are the same, with no
index rebuilds, no re-analyze, etc. then you could check the whole v$parameter
list for changes between versions.

What settings, in particular, do you have for compatible and optimizer_features_enabled ?

Also consider looking at the x$ksppi
parameters for changes to hidden
parameters.

It's probably not a patch problem issue if are convinced that there is a significant increase in hash joins, it's more likely to be a statistical change in the database
somewhere, or a change in the optimizer
in the treatment of the statistics.

--
Jonathan Lewis
http://www.jlcomp.demon.co.uk

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Practical Oracle 8i: Building Efficient Databases


dias wrote in message <55a68b47.0202010654.ce4fc87_at_posting.google.com>...


>Hi,

>

>I've just upgrade a db from 8.1.6.2 to 8.1.7.0 on a Tru64 5.1a.

>My application is a client-server one.

>

>All the queries run 3 or seconds slower.

>With the explain plan, I've noticed that the optimizer uses more Hash

>in the 8.1.7.0 version than in the 8.1.6.2.

>

>Every thing is the same between the two versions : init.ora, disks,

>machine, RAM, ...

>

>Have I to apply the latest patch set to correct the problem.

>

>Thank you

Received on Fri Feb 01 2002 - 09:06:59 CST