Re: postgresql meltdown on PlanetMath.org

Greg Stark <gsstark@mit.edu>

From: Greg Stark <gsstark@mit.edu>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Aaron Krowne <akrowne@vt.edu>, Sean Chittenden <sean@chittenden.org>, pgsql-performance@postgresql.org
Date: 2003-03-17T15:58:39Z
Lists: pgsql-performance
Tom Lane <tgl@sss.pgh.pa.us> writes:

> Aaron Krowne <akrowne@vt.edu> writes:
> > So, either it is broken, or doing a VACUUM FULL ANALYZE rather than just
> > VACUUM ANALYZE made all the difference.  Is this possible (the latter,
> > we know the former is possible...)?
> 
> If your FSM parameters in postgresql.conf are too small, then plain
> vacuums might have failed to keep up with the available free space,
> leading to a situation where vacuum full is essential.  Did you happen
> to notice whether the vacuum full shrunk the database's disk footprint
> noticeably?

This seems to be a frequent problem. 

Is there any easy way to check an existing table for lost free space?

Is there any way vauum could do this check and print a warning suggesting
using vaccuum full and/or increasing fsm parameters if it finds such?

--
greg