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From:John Ragan Date:November 11 2002 10:00pm
Subject:Re: RE: MySql 4.1 Sub Selects and not stored procedures
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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" <daniel@stripped>
> To: "Victoria Reznichenko" <victoria.reznichenko@stripped>;
> <mysql@stripped>
> 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@stripped]
> > Sent: Monday, November 11, 2002 11:00 PM
> > To: mysql@stripped
> > 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
> >
> >
> > --
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> > /_/  /_/\_, /___/\___\_\___/   MySQL AB / Ensita.net
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> >
> >
> >
> >
> >
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> 
> 



-- 
        John Ragan
        john@stripped
        http://www.CoreReader.com/ 

Thread
MySql 4.1 Sub SelectsGreg Matthews10 Nov
  • Re: MySql 4.1 Sub SelectsJeremy Zawodny10 Nov
  • Re: MySql 4.1 Sub SelectsGreg Matthews10 Nov
    • Re: MySql 4.1 Sub SelectsJeremy Zawodny10 Nov
  • Re: MySql 4.1 Sub SelectsJocelyn Fournier10 Nov
  • Re: MySql 4.1 Sub SelectsGreg Matthews10 Nov
    • Re: MySql 4.1 Sub SelectsJeremy Zawodny10 Nov
  • Re: MySql 4.1 Sub SelectsHarald Fuchs10 Nov
  • Re: MySql 4.1 Sub SelectsGreg Matthews10 Nov
  • Re: MySql 4.1 Sub SelectsMichael T. Babcock11 Nov
  • Re: MySql 4.1 Sub SelectsGreg Matthews11 Nov
RE: MySql 4.1 Sub Selectsdaniel11 Nov
  • re: RE: MySql 4.1 Sub SelectsVictoria Reznichenko11 Nov
    • RE: RE: MySql 4.1 Sub SelectsDan Rossi11 Nov
      • Re: RE: MySql 4.1 Sub Selects and not stored proceduresGreg Matthews11 Nov
        • RE: RE: MySql 4.1 Sub Selects and not stored proceduresArthur Fuller11 Nov
          • Re: RE: MySql 4.1 Sub Selects and not stored proceduresGreg Matthews11 Nov
        • Re: MySql 4.1 Sub Selects and not stored proceduresDan Nelson11 Nov
        • Re: RE: MySql 4.1 Sub Selects and not stored proceduresJohn Ragan11 Nov
      • Re: MySql 4.1 Sub SelectsMichael T. Babcock11 Nov
re[2]: MySql 4.1 Sub SelectsRichard Morton11 Nov
  • Re: re[2]: MySql 4.1 Sub SelectsLenz Grimmer11 Nov