Re: fsm and vacuum

I understand, but in this case, since the option is offered next to the safe
one, most people won't know it isn't safe.
I certainly didn't until I read this posting. I know generally what
vacuuming does, but I had no idea that postgres offered a potentially
damaging option. Also, PgAdmin sometimes tells me that a table needs
vacuuming, so it is already "advising" people in that area ...

On Fri, Dec 3, 2010 at 9:19 AM, Guillaume Lelarge <guillaume(at)lelarge(dot)info>wrote:

> Le 03/12/2010 15:17, Michael Shapiro a écrit :
> > The document http://wiki.postgresql.org/wiki/VACUUM_FULL says:
> >
> > VACUUM FULL, unlike VACUUM, tuples data that has not been deleted, moving
> it
> > into spaces earlier in the file that have been freed. Once it's created a
> > free space at the end of the file, it truncates the file so that the OS
> > knows that space is free and may be reused for other things. Moving
> in-use
> > data around this way has some major downsides and side-effects,
> especially
> > the way VACUUM FULL does it. There are better ways to free space if you
> need
> > to and better ways to optimize tables (see below) so *you should
> essentially
> > never use VACUUM FULL*.
> >
> >
> > PgAdmin does not give the user a comparable warning when it goes to
> execute
> > a VACCUM FULL. Given the potential problems with the FULL option, would
> it
> > make sense for PgAdmin to issue a warning to this effect?
> >
>
> I'm not sure this is the role of pgAdmin to warn people they are doing
> potentially stupid things.
>
>
> --
> Guillaume
> http://www.postgresql.fr
> http://dalibo.com
>