I think Waleed's point is that he is yet to see an example where such an optimization has taken place.
cheers connor --- Kevin Toepke <[EMAIL PROTECTED]> wrote: > One of the optimizations behind the DETERMINISTIC > keyword is that Oracle > caches previously computed values. If you pass the > same values into the > function twice, the function body will execute at > least once and at most > twice. You can NOT count on the function body being > executed for each call. > > This is actually a cool feature. Consider a > situation where you are > repeatedly performing time-consuming > computations/lookups. If Oracle caches > previously computed values for you, this can lead to > significant performance > benefits! > > Kevin T > > -----Original Message----- > Sent: Friday, October 03, 2003 9:51 AM > To: Multiple recipients of list ORACLE-L > > > As far as I know, with all current releases of > Oracle, > determinism is purely for function based indexes. > The > deterministic keyword indicates that the function > values when you created the index are still > preserved > when you query it. > > Thus the "first" execution was during index > creation, > and the "second" execution is during subsequent > queries during which the function does not need to > be > executed because it is deterministic. > > (Lame eh?) > > > > --- "Khedr, Waleed" <[EMAIL PROTECTED]> wrote: > > drop table test_det; > > create table test_det (c1 date); > > create or replace function f2 (p1 in number, p2 in > > number) return number > > deterministic is > > pragma autonomous_transaction; > > begin > > insert into test_det values (sysdate); > > commit; > > return(p1 * p2); > > end; > > / > > select f2 (1,3) from dual where f2 (1,3) = 3; > > F2(1,3) > > ---------- > > 3 > > select * from test_det; > > C1 > > --------- > > 02-OCT-03 > > 02-OCT-03 > > It did not save an execution even in the same sql > > call! > > Oracle 9.2.0.2 Solaris 2.8 > > Regards, > > > > Waleed > > > > -- > > Please see the official ORACLE-L FAQ: > > http://www.orafaq.net > > -- > > Author: Khedr, Waleed > > 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). > > ===== > Connor McDonald > web: http://www.oracledba.co.uk > web: http://www.oaktable.net > email: [EMAIL PROTECTED] > > "GIVE a man a fish and he will eat for a day. But > TEACH him how to fish, > and...he will sit in a boat and drink beer all day" > > ________________________________________________________________________ > Want to chat instantly with your online friends? > Get the FREE Yahoo! > Messenger http://mail.messenger.yahoo.co.uk > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.net > -- > Author: =?iso-8859-1?q?Connor=20McDonald?= > 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). > -- > Please see the official ORACLE-L FAQ: > http://www.orafaq.net > -- > Author: Kevin Toepke > 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). ===== Connor McDonald web: http://www.oracledba.co.uk web: http://www.oaktable.net email: [EMAIL PROTECTED] "GIVE a man a fish and he will eat for a day. But TEACH him how to fish, and...he will sit in a boat and drink beer all day" ________________________________________________________________________ Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://mail.messenger.yahoo.co.uk -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: =?iso-8859-1?q?Connor=20McDonald?= 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).
