Re: Performance problems with Oracle 7.3.3.6 on Open VMS Alpha 7.1

From: Uwe Schneider <pi_at_nospam.richard-schneider.de>
Date: Fri, 19 Mar 1999 20:21:52 +0100
Message-ID: <36F2A3D0.1DE45024@nospam.richard-schneider.de>

Hi,

MATTEY Brian wrote:
>
> We've just upgraded from Oracle 7.3.2.3 to 7.3.3.6 on our DEC Alpha system
> and Pro*C generated code now runs at a third of the speed that it used to.
> SQL and PL/SQL code is fine however. Note that all Pro*C code was re PROC'd
> compiled and linked before running.

I experienced the same problem when upgrading from 7.2 to 7.3.3 (AIX), but the performance decay was partially a factor of 1000 (thousand). The reason was that Oracle uses the cost based optimizer from 7.3.3 on (I think). This works only well if you perform ANALYZE runs on your tables and indexes. After explicitly witching back to rule based optimizing the performance was as high as before. Try it!

Uwe

--

Uwe Schneider       | Telefon +49 7251 / 82587
Karlsdorfer Str. 31 | Mail    pi_at_richard-schneider.de
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Linux - OS al dente! Received on Fri Mar 19 1999 - 13:21:52 CST