Stephane, Three things I don't need to tell you about your example:
Prior to CPU-costing in 9, the order of single table predicates can have a dramatic impact on CPU without changing the amount of logical I/O. Logical I/O should always include the statistics "buffer is pinned count" - it's just another way of visiting a buffer - the cost of getting there is cheaper, but still not free. Any change to the query could modify the number of times a pl/sql function is called - which could be far more CPU intensive than all the logical I/O effects anyway. Regards Jonathan Lewis http://www.jlcomp.demon.co.uk The educated person is not the person who can answer the questions, but the person who can question the answers -- T. Schick Jr One-day tutorials: http://www.jlcomp.demon.co.uk/tutorial.html ____UK_______April 8th ____UK_______April 22nd ____Denmark__May 21-23rd ____USA_(FL)_May 2nd Three-day seminar: see http://www.jlcomp.demon.co.uk/seminar.html ____UK_(Manchester)_May ____Estonia___June (provisional) ____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" <[EMAIL PROTECTED]> Sent: 01 April 2003 22:14 > Here is the result : > > original all_rows > Steps in plan 176 166 > recursive calls 259 1776 > db block gets 72 324 > consistent gets 474556 6700 > physical reads 12497 1981 > redo size 152 21736 > bytes to client 3060 3060 > bytes from client 5811 4500 > SQL*Net roundtrips 2 2 > memory sorts 10 13 > disk sorts 0 0 > rows 6 6 > Elapsed time 24.75 > 4 mn > > Although LIOs have drastically reduced, and so have PIOs, our time is > about 10 times worse! -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Jonathan Lewis INET: [EMAIL PROTECTED] 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: [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).
