Re: Name for new VACUUM - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: Name for new VACUUM
Date
Msg-id 3B6D8497.55E3094A@tm.ee
Whole thread Raw
In response to Re: Name for new VACUUM  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Bruce Momjian wrote:
> 
> > Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > >> Not necessarily.  Concurrent VACUUM does truncate the relation if it can
> > >> do so conveniently --- for example, it will successfully reclaim space
> > >> if you do "DELETE FROM foo; VACUUM foo;".  It just doesn't try as hard
> > >> as the older VACUUM code does.
> >
> > > But it will not reclaim from UPDATE.
> >
> > What?  I have no idea what you mean by that.
> 
> I meant that UPDATE of all rows in a table put the new rows at the end.

OTOH if you do it twice it will reclaim ;)

UPDATE everything;
VACUUM;
UPDATE everything;
VACUUM;

---------------
Hannu


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