"Ryan" <rgaffuri_at_cox.net> wrote in message news:<cpoW8.68471$DB.1742984_at_news1.east.cox.net>...
> What about performance comparisons? I know that in some cases pl/sql tables
> are useful if you need to do a series of joins and /or sorts you can load
> one table into memory by putting it in a pl/sql table.
>
> How is the data in a GTT stored? I would assume there is no redo and if
> there is no redo, DBWR does not write it to the data file. So is it stored
> in memory and in the temporary tablespace?
>
>
> "Keld Nielsen" <keldnielsen_at_image.dk> wrote in message
> news:M8iW8.157$s76.32298_at_news010.worldonline.dk...
> > Hi Richard,
> > Just a small comment (embedded)
> >
> > "Richard Foote" <richard.foote_at_bigpond.com> wrote
> > in message
> > news:TsgW8.30694$Hj3.92875_at_newsfeeds.bigpond.com..
> > .
> > > Hi
> > >
> > > Just to add to what Robert has said.
> > >
> > > A GTT is actually quite permanent, it's the data
> within it that's temporary
> > > (either at a transaction or session level).
> Therefore you can potentially
> > > access data in a GTT through many PL/SQL block
> executions.
> > >
> > > A PL/SQL table is temporary, period, as it's a
> memory structure that exists
> > > only for the life of the PL/SQL block.
> >
> > if it's created in a package body (or spec) it
> > will exist during
> > the life of a session - or am I wrong here ?
> >
> > >
> > > Therefore it depends on what you're trying to
> achieve.
> > >
> > > Horses for courses and that sort of thing.
> > >
> > > Richard
> > >
> > >
> > >
> > >
> > > "R Chin" <rchin_at_panix.com> wrote in message
> > > news:agc37s$cts$2_at_reader2.panix.com...
> > > > They are different objects...
> > > > PL/SQL Table = memory structure, like array,
> can't use SQL...
> > > > GTT = real db table that's wriiten to disk,
> got rowids.... any DML...you
> > > > know what to do
> > > > with ordinary table you kno what to do with
> GTT.
> > > > All depends on your needs...you use what you
> need to do what you want to
> do.
> > > >
> > > > Robert
> > > >
> > > >
> > > > Tony Crispin wrote in message ...
> > > > >I am looking for a bit of advice/information:
> > > > >
> > > > >I need to understand the performance
> implications of using either global
> > > > >temporary tables or pl/sql tables for storing
> temporary data generated
> > > > >during a session.
> > > > >
> > > > >
> > > > >How are pl/sql tables implemented by Oracle;
> > > > >What is the benefit of using one method
> rather than the other;
> > > > >When should one method be used rather than
> the other?
> > > > >
> > > > >Thanks in advance
> > > > >Tony
> > > > >
One consideration is that the maximum size of a pl/sql table is
OS/port dependent. A developer ran some testing for me back on what
was probably version 7.3 and the limit we hit seemed to be around 10M.
Depending on your data size requirements this might be a factor that
you need to consider, and test for on your platform.
Received on Tue Jul 09 2002 - 07:36:42 CDT
