Re: Space occupied by Postgres index.

A regular vacuum will free space reclaimed at the end of a table.
In normal use, your optimum space consumption is that needed to
hold the current table data plus the space needed to hold the
old deleted or modified data until a regular vacuum can make it
available for reuse. In addition, using HOT updates with table
fillfactor < 100, can greatly reduce table fragmentation and
bloating.

Cheers,
Ken

On Tue, Nov 30, 2010 at 11:12:23PM +0530, Shridhar Polas wrote:
> Thanks for a quick response Ken.
>
> One more query:-
>
> If I do not perform VACUUM FULL and REINDEX, does Postgres reclaimed the
> space automatically when number of records in tables reduce after touching
> some limit? I mean the total disk space consumed by Postgres would ever be
> decline at any point without performing VACUUM FULL and REINDEX?
>
> In my test setup I found that the disk space consumed by Postgers is not
> getting declined even after deleting records from tables, if I do not
> perform VACUUM FULL and REINDEX.
>
> Thanks again
> Shridhar
>
> -----Original Message-----
> From: Kenneth Marshall [mailto:ktm(at)rice(dot)edu]
> Sent: Tuesday, November 30, 2010 10:59 PM
> To: Shridhar Polas
> Cc: pgsql-admin(at)postgresql(dot)org
> Subject: Re: [ADMIN] Space occupied by Postgres index.
>
> On Tue, Nov 30, 2010 at 10:56:53PM +0530, Shridhar Polas wrote:
> > Hi,
> >
> >
> >
> > I am facing a problem where indexes creates on some tables are
> > occupying huge space on disk and it seems to me that this space is not
> > getting reclaimed even when there are very few record in an associated
> table.
> >
> >
> >
> > When I ran full vacuum the disk space was reclaimed occupied by tables
> > but not by disk space occupied by indexes.
> >
> >
> >
> > Can somebody please tell me when disk space occupied by Postgres index
> > is reclaimed, without performing re-indexing on those tables?
> >
> >
> >
> > Thanks,
> >
> > Shridhar
> >
>
> VACUUM FULL will cause index bloat. You will need to REINDEX to recover the
> space. Note, you should not really need to use VACUUM FULL in a normal
> correctly configured system.
>
> Cheers,
> Ken
>
>