the EXISTS logic is ugly in as sql statement. does that count? seems like ugly should count.
> > hey, can i hijack my message back?...this thread is about the performance of > subselects, not stored procedures. go write your own message :-)... > > so....the original question is if someone would be nice enough to answer.. > > ====> Do any MySql coders writing subselects in 4.1 know whether EXISTS will > outperform an equivalent query written as a join. <===== > > Typically, db vendors recommend you use an exists clause, not a join when > testing for the presence of child data because it's faster. > > e.g. > > 4.1 version (faster?) > --------------------- > select person.person_id, person.name from person where exists ( select 1 > from invoice where invoice.paid is null and invoice.person_id = > person.person_id) > > vs > > 4.0 version (slower?) > ---------------------- > select DISTINCT person.person_id, person.person_name from person, invoice > where person.person_id = invoice.person_id and invoice.paid is null > > > Thanks, > Greg. > > ----- Original Message ----- > From: "Dan Rossi" <[EMAIL PROTECTED]> > To: "Victoria Reznichenko" <[EMAIL PROTECTED]>; > <[EMAIL PROTECTED]> > Sent: Monday, November 11, 2002 11:04 PM > Subject: RE: RE: MySql 4.1 Sub Selects > > > > damn , i read it was 4.1 i guess we have to wait a bit then, i wish i > could > > program some c ++ to hurry it along a bit, i dont really have access to > DB's > > like oracle to learn stored procedure stuff > > > > -----Original Message----- > > From: Victoria Reznichenko [mailto:victoria.reznichenko@;ensita.net] > > Sent: Monday, November 11, 2002 11:00 PM > > To: [EMAIL PROTECTED] > > Subject: re: RE: MySql 4.1 Sub Selects > > > > > > daniel, > > Monday, November 11, 2002, 3:51:25 AM, you wrote: > > > > d> will 4.1 hopefully have stored procedure functionality ? > > > > Nope. > > Stored procedures will be implemented around v5.0 > > > > > > -- > > For technical support contracts, goto https://order.mysql.com/?ref=ensita > > This email is sponsored by Ensita.net http://www.ensita.net/ > > __ ___ ___ ____ __ > > / |/ /_ __/ __/ __ \/ / Victoria Reznichenko > > / /|_/ / // /\ \/ /_/ / /__ [EMAIL PROTECTED] > > /_/ /_/\_, /___/\___\_\___/ MySQL AB / Ensita.net > > <___/ www.mysql.com > > > > > > > > > > > > --------------------------------------------------------------------- > > Before posting, please check: > > http://www.mysql.com/manual.php (the manual) > > http://lists.mysql.com/ (the list archive) > > > > To request this thread, e-mail <[EMAIL PROTECTED]> > > To unsubscribe, e-mail > > <[EMAIL PROTECTED]> > > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > > > > > > --------------------------------------------------------------------- > > Before posting, please check: > > http://www.mysql.com/manual.php (the manual) > > http://lists.mysql.com/ (the list archive) > > > > To request this thread, e-mail <[EMAIL PROTECTED]> > > To unsubscribe, e-mail > <[EMAIL PROTECTED]> > > Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php > > > > -- John Ragan [EMAIL PROTECTED] http://www.CoreReader.com/ --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
