> Like an IN query as Robert says would definitely work
this will _not_ work, there is a limit to the length of your SQL string that
you can execute!
instead reuse the where clause!
see my previous post.
Filip
~
Namaste - I bow to the divine in you
~
Filip Hanik
Software Architect
[EMAIL PROTECTED]
www.filip.net
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Gina
> Celiko
> Sent: Monday, May 07, 2001 8:00 PM
> To: [EMAIL PROTECTED]
> Subject: RE: [JBoss-dev] TODO: JBossCMP 1.1 FAST!
>
>
> Indeed, just one query should be enough reducing the
> extra database trip. Even a dynamically created
> query(of course optimized), will be faster then two
> database trips (even if the database trips were using
> stored procs.)
> You can dynamically join whatever you want, and the
> data coming back unless they are blobs or clobs or
> raws
> is not going to exceed the bandwidth.
> and anything else joined together.
> Still can apply the rules of optimization ofcourse.
>
> --- Robert Nicholson <[EMAIL PROTECTED]> wrote:
> > If you have the keys why not just build an IN clause
> > type query?
> >
> > > -----Original Message-----
> > > From:
> > [EMAIL PROTECTED]
> > >
> >
> [mailto:[EMAIL PROTECTED]]On
> > Behalf Of Jay
> > > Walters
> > > Sent: Monday, May 07, 2001 6:49 PM
> > > To: 'Filip Hanik ';
> > '[EMAIL PROTECTED] '
> > > Subject: RE: [JBoss-dev] TODO: JBossCMP 1.1 FAST!
> > >
> > >
> > > Why not just one query?
> > >
> > > -----Original Message-----
> > > From: Filip Hanik
> > > To: [EMAIL PROTECTED]
> > > Sent: 5/7/01 9:39 PM
> > > Subject: RE: [JBoss-dev] TODO: JBossCMP 1.1 FAST!
> > >
> > > > Sorry lets put that in context, need to
> > eliminate N+1 query problem
> > > first.
> > > > Reduce trips to the database is #1. Then make
> > the trips more
> > > efficient.
> > >
> > > yes, 2 queries should be enough assuming that one
> > bean's data can be
> > > contained within one row.
> > >
> > > query 1: is the finder query that returns the
> > primary key objects.
> > > query 2: is the retrieve query that returns the
> > data for the actual
> > > entity
> > > beans.
> > >
> > > if query 2 is constructed in such a way that
> > > a) select ...all data that needs to be
> > collected... from table
> > > b) where ...same where clause as the find
> > query...AND (additional joins
> > > if
> > > needed)
> > >
> > > as you can see. since query 1 and query 2 should
> > have similar where
> > > clauses,
> > > there is no need to execute "select ...data...
> > from table where key = ?"
> > > N
> > > number of times.
> > >
> > > does this makes sense to you, so in this case each
> > findXXX:Collection
> > > would
> > > only require two queries.
> > >
> > >
> > > Filip
> > >
> > > ~
> > > Namaste - I bow to the divine in you
> > > ~
> > > Filip Hanik
> > > Software Architect
> > > [EMAIL PROTECTED]
> > > www.filip.net
> > >
> > >
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