Thread: Question about space usage:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I recently upgraded from 7.3.4 to 7.4.  Besides the PostGreSQL change I
updated my schema to pull out all OIDs and 'set storage external'.

With PostGreSQL V7.3.4, a completely reindexed and vacuumed(not-full) foot
print was 5.2 gig.  Now some of the disk space(probably 10-15 % was waiting
in the FSM to be used).  However, 7.4 comes up at 2.3 gig.

Don't get me wrong, I'm not complaining.  I was under the impression that text
was compressed by default and that changing from compressed to
'non-compressed' would result in a larger foot print.  Is there something I
am missing?

- --
Jeremy M. Guthrie
Systems Engineer
Berbee
5520 Research Park Dr.
Madison, WI  53711
Phone:  608-298-1061

Berbee...Decade 1.  1993-2003
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (GNU/Linux)

iD8DBQFABsHVqtjaBHGZBeURAp3tAKCTe9SjnPEU5V25KnxWZHD4ulXIXwCfd45O
Cf9lRBReCjv9fKyglR+dSM8=
=GpkI
-----END PGP SIGNATURE-----

"Jeremy M. Guthrie" <jeremy.guthrie@berbee.com> writes:
> With PostGreSQL V7.3.4, a completely reindexed and vacuumed(not-full) foot
> print was 5.2 gig.  Now some of the disk space(probably 10-15 % was waiting
> in the FSM to be used).  However, 7.4 comes up at 2.3 gig.

First thought is that your 7.3 DB was suffering from index bloat (I know
you said you reindexed, but did you get everything including system
indexes?).  The only material space savings in 7.4 over 7.3 as far as
raw data size goes is Manfred's row header size reduction (8 bytes per
row), which wouldn't account for that kind of difference unless you had
a huge number of very narrow rows ...

> Besides the PostGreSQL change I updated my schema to pull out all OIDs
> and 'set storage external'.

Removing OIDs would save another 4 or 8 bytes per row (depending on what
hardware you're on).

            regards, tom lane