Re: 10g vs 9i

  • From: "Ujang Jaenudin" <ujang.jaenudin@xxxxxxxxx>
  • To: "Peter McLarty" <p.mclarty@xxxxxxxxxx>
  • Date: Tue, 12 Jun 2007 12:48:06 +0700


for the oltp users, they didn't give me an alert.
but i'm testing a report as exactly so many joins, even the latest
result comes from the result set not from table directly,,,, something

select * from (select .... from a,b where ... ( select .....))....

tested on 9i it tooks only 30min, but on 10g rac, till 2hours and never end.. :(

could you point me which v$ ?


On 6/12/07, Peter McLarty <p.mclarty@xxxxxxxxxx> wrote:
Hi Ujang

I have seen this behaviour. It happens going from 9 to 10 at any level.
In the case I had was due to things doing joins whose performance
changed due to the effects of the optimiser.

You will have to take each case by itself and analyse it. I would
consult with your business users for their worst performer and isolate
the cause of that and then work back from there removing the most
expensive issues

It is likely as you take it apart you may fix a number of issues at the
same time

Look out for joins to v$ views as these performed badly



-----Original Message-----
From: Ujang Jaenudin [mailto:ujang.jaenudin@xxxxxxxxx]
Sent: Tuesday, 12 June 2007 03:14 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: 10g vs 9i


recently i have a dev machine 10g on itanium ia-64 another linux is
itanium ia-64 with 9i

the performance on 10g ( is dropped for almost 1/3 from the 9i,
if someone has the same experiences, pls share....

all these parameters doesn't help either...
alter system set optimizer_features_enable='9.2.0' scope=both; alter
system set "_optimizer_cost_based_transformation" =on scope=both; alter
system set "_gby_hash_aggregation_enabled" = TRUE scope=both;



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