Re: Optimizer help, get query to run as good as with RULE hint

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Mon, 17 Feb 2003 03:58:38 -0800
Message-ID: <F001.0054F2F0.20030217035838@fatcity.com>

The cartesian merge join in the last
two plans is interesting feature. It's
the sort of thing you associate with
very small tables - not tables which
look as if they might be returning
large volumes of data.

Regards

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

Coming soon one-day tutorials:
Cost Based Optimisation
Trouble-shooting and Tuning
Indexing Strategies
(see http://www.jlcomp.demon.co.uk/tutorial.html )

____UK_______March 19th
____USA_(FL)_May 2nd

Next Seminar dates:
(see http://www.jlcomp.demon.co.uk/seminar.html )

____USA_(CA, TX)_August

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html

-----Original Message-----
To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com> Date: 17 February 2003 05:51
hint

>
>Here's one bad SQL I am working on right now.
>Even the execution plan changes with a different SORT_AREA_SIZE !
>
>9.2.0.2 on Tru64 :
>
>Query Plan
>---------------------------------------------------------------------

---

>SELECT STATEMENT Cost = 179625268
> SORT UNIQUE
> HASH JOIN
> TABLE ACCESS FULL RECIPE
> HASH JOIN
> TABLE ACCESS FULL PRCD
> HASH JOIN
> TABLE ACCESS FULL PRCD_INSTRUCTION_RUNSHEET
> MERGE JOIN CARTESIAN
> HASH JOIN
> TABLE ACCESS FULL PART
> TABLE ACCESS FULL PRCD_INSTRUCTION
> BUFFER SORT
> TABLE ACCESS FULL STAGE
>

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Jonathan Lewis
  INET: jonathan_at_jlcomp.demon.co.uk

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 Mon Feb 17 2003 - 05:58:38 CST