Re: Postgresql 'eats' all mi data partition - Mailing list pgsql-bugs

On Thu, 25 Sep 2003, Javier Carlos wrote:

> Quoting Stephan Szabo <sszabo@megazone.bigpanda.com>:
>
> > On Thu, 25 Sep 2003, Javier Carlos wrote:
> >
> > >
> > ============================================================================
> > >                         POSTGRESQL BUG REPORT TEMPLATE
> > >
> > ============================================================================
> > >
> > >
> > > Your name        :    Javier Carlos Rivera
> > > Your email address    :    fjcarlos ( at ) correo ( dot ) insp ( dot ) mx
> > >
> > >
> > > System Configuration
> > > ----------------------
> > >   Architecture (example: Intel Pentium)        : Intel Pentium 4
> > >
> > >   Operating System (example: Linux 2.0.26 ELF)       : Debian GNU/Linux
> 3.0
> > 2.4.21
> > >
> > >   RAM                          : 256 MB
> > >
> > >   PostgreSQL version (example: PostgreSQL-6.3.2)  : PostgreSQL-7.3.4
> > >
> > >   Compiler used (example:  gcc 2.7.2)          : 2.95.4
> > >
> > >
> > >
> > > Please enter a FULL description of your problem:
> > > -------------------------------------------------
> > >     On Thursday Bruce Momjian was at Mexico; I saw him and asked about
> > > this problem. He told me to write to this e-mail.
> > >
> > >     When I do a simple 'UPDATE' PostgreSQL 'eats' all my partition space
> > > of my data directory. For example:
> > >
> > > ***** My data directory is in /var
> > > ***** BEFORE I do the UPDATEs I got this from df:
> > > OPORTUNIDADES:~# df
> > > Filesystem           1k-blocks      Used Available Use% Mounted on
> > > /dev/hda2              2885812     14372   2724848   1% /
> > > /dev/hda1             14421344   1195132  12493652   9% /var
> > > /dev/hda3              7692908    888560   6413568  13% /usr
> > > /dev/hda6             12491804     22704  11834536   1% /javier
> > > /dev/hda7              1494204     23936   1394364   2% /home
> > >
> > >
> > > ***** Then I do the UPDATEs:
> > > **** The updates are of this type :
> > > UPDATE tbl_personas SET "PIDFOLIO"=-2 WHERE "PIDFOLIO" IS NULL;
> > > UPDATE tbl_personas SET "P5_1"=-2 WHERE "P5_1" IS NULL;
> > > UPDATE tbl_personas SET "P4PAQ"=-2 WHERE "P4PAQ" IS NULL;
> > > UPDATE tbl_personas SET "P5_4"=-2 WHERE "P5_4" IS NULL;
> > > UPDATE tbl_personas SET "P5_5"=-2 WHERE "P5_5" IS NULL;
> > > UPDATE tbl_personas SET "P36_4"=-2 WHERE "P36_4" IS NULL;
> > > ..
> > > UPDATE table_name SET column_name = -2 WHERE column_name IS NULL;
> > > ..
> >
> > If you're not vacuuming, you're going to have a potentially large
> > number of dead rows.  Does a vacuum between updates or a vacuum full at
> > the end bring the space usage down to something reasonable?
> >
>
>    I did a vacuumbdb after the updates, and the space usage didn't down to
> something reasonable. For example, I had a 250MB database, then I did about
> 300 query updates, and mi partition growed up until fill all mi data partition
> space of 15GB. After that I did an vacuumdb and only the space down 100MB.
> After that I DROPPED the database, and the space down ALL the 15GB; It's very
> weird, don't you think?

Did you use -f on the vacuumdb?  If not, it did a normal vacuum (which
isn't likely to help) not a full vacuum.