Re: Global Temp Tables - lots of redo in 9i, why? how to fix?

"Which is exactly what happens when you insert rows into any table and don't issue a commit."

Global temporary tables can persist your data across a session or across a transaction - it's your choice.

"DA Morgan" <damorgan_at_exesolutions.com> wrote in message news:3E60D261.AFBA63B6_at_exesolutions.com...
> Comments interspersed.
>
> Tim X wrote:
>
> > >>>>> "DA" == DA Morgan <damorgan_at_exesolutions.com> writes:
> >
> > <snipped>
> >
> > I've used GTTs once and can think of another area where they can be
> > useful. However, in reality, I don't treat them as temporary tables so
> > much as tables which have temporary data - the table stays, but the
> > data does not.
>
> Which is exactly what happens when you insert rows into any table and
don't
> issue a commit.
>
>
> > The place where I have used them is in an application which needs to
> > collect and process data from a number of remote databases and put the
> > results into a permanent table. While I was able to find a solution
> > which did this without using any temporary tables, I found the use of
> > a GTT was a bit faster and more importantly, resulted in simpler and
> > clearer SQL. The GTT solution was selected in the end because it was
> > simpler to follow and therefore would (hopefully) be simpler to
> > maintain and I always try to put an emphasis on maintenance.
>
> I agree that this could be desirable. But my statement was that I had yet
to
> find anytime that they were "needed" meaning "required".
>
> > The second possible use of GTTs which I can think of is in
> > applications where you have to maintain some data for a temporary
> > period and you possibly don't want other sessions to be aware of data
> > which they have not placed in the table. A possible example could be a
> > web application where you want to maintain some sort of state
> > information, but only until the session ends and possibly you have
> > multiple sessions, but you don't want to maintain session identifiers.
> > Again, this is not really a temporary table as the table is permanent,
> > but the data is temporary. I find the special features of GTTs over
> > regular tables meet these sort of situations a lot better.
>
> This is exactly the behavior of an uncommitted insert into a heap table.
Not
> that a GTT won't work ... but so will any table.
>
> >
> > So, while I agree 100% that using temporary tables within Oracle
> > should be avoided (e.g. tables which are created and (hopefully)
> > removed) simply to hold intermediate data during some complex
> > processing etc), I do think temporary global
> > tables can be very useful in some situations because of their special
> > features (such as data only being visible to the session which
> > inserted it, automatic removal of data when the session exits, no
> > rollback overhead etc).
> >
> > Possibly Global Temporary Tables should have been called Global
> > Temporary Data Tables?
> >
> > Tim
> >
> > --
> > Tim Cross
> > The e-mail address on this message is FALSE (obviously!). My real e-mail
is
> > to a company in Australia called rapttech and my login is tcross - if
you
> > really need to send mail, you should be able to work it out!
>
> The only value I see is the automatic removal which avoids my needing to
write
> one line of code. The other functionality is nothing more than INSERT
without a
> COMMIT.
>
> Or is there something I'm missing?
>
> Daniel Morgan
>
Received on Sat Mar 01 2003 - 11:32:22 CST