select /*+ rule */ ...
cut the execution time to nil. Thanks to Charlie Mengler for help and Tim Gorman for a note in his "i.sql" that solved the problem. -----Original Message----- [mailto:[EMAIL PROTECTED]] Sent: Tuesday, May 14, 2002 3:09 PM To: Multiple recipients of list ORACLE-L 2-cpu, 220mhz, 32-bit HPUX 11.0. Oracle 8.1.7.0.0 Could someone explain what's going on here? This SQL takes no time at all : select substr(username , 1, 12) "User" , substr(lock_type, 1, 18) "Lock Type" , substr(mode_held, 1, 18) "Mode Held" from sys.dba_lock a , v$session b where /*lock_type not in ('Media Recovery','Redo Thread') and*/ a.session_id = b.sid; with explain plan: SELECT STATEMENT Optimizer=CHOOSE (Cost=70 Card=1 Bytes=148) NESTED LOOPS (Cost=70 Card=1 Bytes=148) NESTED LOOPS (Cost=60 Card=1 Bytes=141) NESTED LOOPS (Cost=20 Card=1 Bytes=107) FIXED TABLE (FULL) OF X$KSUSE (Cost=10 Card=1 Bytes=30) FIXED TABLE (FIXED INDEX #1) OF X$KSUSE (Cost=10 Card=1 Bytes=77) VIEW OF GV$_LOCK UNION-ALL VIEW OF GV$_LOCK1 (Cost=20 Card=2 Bytes=162) UNION-ALL FIXED TABLE (FULL) OF X$KDNSSF (Cost=10 Card=1 Bytes=94) FIXED TABLE (FULL) OF X$KSQEQ (Cost=10 Card=1 Bytes=94) FIXED TABLE (FULL) OF X$KTADM (Cost=10 Card=1 Bytes=94) FIXED TABLE (FULL) OF X$KTCXB (Cost=10 Card=1 Bytes=94) FIXED TABLE (FIXED INDEX #1) OF X$KSQRS (Cost=10 Card=100 Bytes=700) whereas an uncommented predicate consumes 40 minutes of CPU (sez TOP) with this explain plan: SELECT STATEMENT Optimizer=CHOOSE (Cost=70 Card=1 Bytes=148) NESTED LOOPS (Cost=70 Card=1 Bytes=148) NESTED LOOPS (Cost=30 Card=1 Bytes=114) MERGE JOIN (CARTESIAN) (Cost=20 Card=1 Bytes=37) FIXED TABLE (FULL) OF X$KSUSE (Cost=10 Card=1 Bytes=30) SORT (JOIN) (Cost=10 Card=1 Bytes=7) FIXED TABLE (FULL) OF X$KSQRS (Cost=10 Card=1 Bytes=7) FIXED TABLE (FIXED INDEX #1) OF X$KSUSE (Cost=10 Card=1 Bytes=77) VIEW OF GV$_LOCK UNION-ALL VIEW OF GV$_LOCK1 (Cost=20 Card=2 Bytes=162) UNION-ALL FIXED TABLE (FULL) OF X$KDNSSF (Cost=10 Card=1 Bytes=94) FIXED TABLE (FULL) OF X$KSQEQ (Cost=10 Card=1 Bytes=94) FIXED TABLE (FULL) OF X$KTADM (Cost=10 Card=1 Bytes=94) FIXED TABLE (FULL) OF X$KTCXB (Cost=10 Card=1 Bytes=94) If it jams, force it. If it breaks, it needed replacing anyway. --John F Duval -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Kirsch, Walter J (Northrop Grumman) 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: Kirsch, Walter J (Northrop Grumman) 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).
