A few questions and suggestions:
1) What version of Oracle are you running?
2) Identify the SQL that is run most frequently and compare the explain
plans under RULE and CHOOSE
3) Do the same with any reports. These are most likely to suddenly do
ridiculous sort/merge joins killing performance.
4) Did you analyze all your tables *except* those owned by SYS (analyzing
SYS owned tables will give very poor performance)
This is actually a great opportunity for you. I learned a huge amount about
reading Explain Plans and tuning SQL when we made our switch.
Jay Miller
x48355
-----Original Message-----
Sent: Tuesday, January 22, 2002 12:06 PM
To: Multiple recipients of list ORACLE-L
I have a large app that is still running rule based, we are finally going to
take the plunge and try to start going cost based. The first time we tried
this the performance was terrible in a lot of places. Does anyone have any
good white papers or hints/tips on what to look for on areas that might be
problems or pitfalls?
tia
... --- ... .... . .-.. .--. -- . .. .----. -... . . -. .--. .-. --- -...
.-..
John B. Shaw
(ribit)
/
o o
( -- )
/\( , ,)/\
^^ ^^ ^^ ^^
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Shaw John-P55297
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (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).
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Miller, Jay
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (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).
