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Re: TEMPORARY TABLE

From: rjamya <rjamya_at_gmail.com>
Date: Wed, 27 Oct 2004 14:52:19 -0400
Message-ID: <9177895d041027115230b6bcbf@mail.gmail.com>


I have seen lots of code that were doign truncates ... you know just-to-be-safe. Luckily we found this in devl (and I had heard about this issue of truncates and gtt very recently then). We mamaged to convince development to replace truncate to delete and the world rested easily.

and by dynamic sampling ... since you can't collect statistics on GTTs, it is preferable to use dynamic sampling, which might be a tad better than oracle's default values for stats. Jonathan Lewis gave a very very interesting talk on this topic at Hotsos'04.

Raj

On Wed, 27 Oct 2004 14:41:58 -0400, Mercadante, Thomas F <thomas.mercadante_at_labor.state.ny.us> wrote:
> Raj,
>
> Why would you want to do truncates on these tables? By definition, nothing
> is saved in these tables when the session ends. So you never need to
> perform a truncate.
>
> I do nothing special with this table, at is is used constantly by lots of
> people all day long. I never perform a truncate on this table.
>
>
>
> Tom Mercadante
> Oracle Certified Professional
>
> -----Original Message-----
> From: rjamya [mailto:rjamya_at_gmail.com]
> Sent: Wednesday, October 27, 2004 2:31 PM
> To: thomas.mercadante_at_labor.state.ny.us
> Cc: oracledbam_at_hotmail.com; oracle-l_at_freelists.org
> Subject: Re: TEMPORARY TABLE
>
> well tom is almost 99% there ... there is the rest of the story ... about
> GTTs that
>
> 1. you better use dynamic_sampling with them
> 2. any even one session is useing it, you can't perform most DDLs 3. forget
> doing truncates on them, KGopal probably has the proof.
>
> otherweise they work almost as advertised ...
> Raj
>
> On Wed, 27 Oct 2004 14:20:03 -0400, Mercadante, Thomas F
> <thomas.mercadante_at_labor.state.ny.us> wrote:
> > Seema,
> >
> > I use Global Temporary Tables all the time. They are memory
> > structures. Very fast. Very easy to set up. No problems at all.
> >
> > Good Luck
> >
> > Tom Mercadante
> > Oracle Certified Professional
> >
> >
> >
> >
> > -----Original Message-----
> > From: Seema Singh [mailto:oracledbam_at_hotmail.com]
> > Sent: Wednesday, October 27, 2004 1:34 PM
> > To: oracle-l_at_freelists.org
> > Subject: TEMPORARY TABLE
> >
> > Hi,
> > Is any performance problem if we go with TEMPORARY table?
> > any thoughtS?
> > thx
> >
> > _________________________________________________________________
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Received on Wed Oct 27 2004 - 13:48:20 CDT

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