In that same vein, ( or is it vane, or maybe even vain? ;) I tried removing a correlated subquery from a bit of SQL just yesterday.
It was duly replaced with an inline view, and the time to run the query increased by %20. :) Jared On Saturday 16 March 2002 01:53, Jonathan Lewis wrote: > On that line, I've just had a note from Gaja > about my commentary on the line: > > "Rewrite all correlated subqueries using in-line views". > > He was concerned that I may not think the > advice valid. So let me say quite categorically > that the comment was not a criticism of the > technique. > > Converting a subquery into a join is a strategy > which will very often result in significant performance > benefits and Gaja is, I think, the first person I > have seen make a very special mention of it in > a public paper. (No doubt someone will correct > me on that quite soon). > > My point was that although it is not the automatic, > the only, or even necessarily the correct solution > to the sight of a correlated subquery, Gaja's paper > will, one day, be quoted as the definitive proof > that you should ALWAYS do it. And such is the > stuff of the urban legend. > > > > Jonathan Lewis > http://www.jlcomp.demon.co.uk > > Next Seminar - UK, April 3rd - 5th > http://www.jlcomp.demon.co.uk/seminar.html > > Host to The Co-Operative Oracle Users' FAQ > http://www.jlcomp.demon.co.uk/faq/ind_faq.html > > Author of: > Practical Oracle 8i: Building Efficient Databases > > > -----Original Message----- > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > Date: 16 March 2002 09:27 > > |You're cheating. Most advice containing 'always', even only once, > > stands > > |a big chance of becoming a legend very soon. > |-- > |Regards, > | > |Stephane Faroult > |Oriole Ltd -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still 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).
