Re: GLOBAL vs LOCAL temp tables

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl>
Cc: Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp>, tgl(at)sss(dot)pgh(dot)pa(dot)us, pgsql-hackers(at)postgresql(dot)org
Subject: Re: GLOBAL vs LOCAL temp tables
Date: 2003-04-16 03:17:59
Message-ID: 200304160317.h3G3Hx903760@candle.pha.pa.us
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Alvaro Herrera wrote:
> On Wed, Apr 16, 2003 at 10:09:38AM +0900, Tatsuo Ishii wrote:
> > The real problem with current temp tables is the implementation. I see
> > very quick growth of system catalogs with heavy use of temp
> > tables(some hundred mega bytes per week on a busy system for
> > example). To fix the system catalogs, we have to stop postmaster and
> > have to do reindex. This is truly a pain.
>
> This is fixed in 7.4 already. It wasn't a problem with temp tables, but
> with btree indexes.

Yes, it is fixed partly, but I want to point out that the fix somewhat
asymetric.

For example, it would be nice to tell people that they should either use
VACUUM several times a day _or_ run VACUUM FULL nightly. The problem
with this simplification is indexes --- VACUUM records free indx pages,
while VACUUM FULL doesn't do anything with empty index pages.

Is there anything we can do to improve this situation? Should VACUUM
FULL record free index pages?

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
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