PostgreSQL's vacuumdb fails to allocate memory for non-root users

[Sven Willenberger]

On Wed, 2005-06-29 at 21:54 +0200, Juergen Dankoweit wrote:
> Hello,
> 
> Am Mittwoch, den 29.06.2005, 14:59 -0400 schrieb Vivek Khera:
> > On Jun 29, 2005, at 9:01 AM, Sven Willenberger wrote:
> > 
> > > Unix user root (and any psql superuser) the vacuum runs fine. It is  
> > > when
> > > the unix user is non-root (e.g. su -l pgsql -c "vacuumdb -a -z") that
> > > this memory error occurs. All users use the "default" class for
> > > login.conf purposes which has not been modified from its installed
> > > settings. Any ideas on how to a) troubleshoot this or b) fix this  
> > > (if it
> > > is something obvious that I just cannot see).
> > 
> > This doesn't make sense: the actual command is executed by the  
> > backend postgres server, so the uid of the client program doens't  
> > make a bit of difference.
> > 
> > You need to see exactly who is generating that error.  It certainly  
> > is not the Pg backend.
> 
> Sorry for that possible stupid question. But why do you think that the
> PG backend does not generate the error?
> I use PostgreSQL since many years under FreeBSD and it is the first time
> to hear from such an error.

As the postgres logfiles have the out of memory error in them it would
appear that it is the backend generating this error. Since, I am
assuming here, dfldsiz and maxdsiz (set in loader.conf at 850MB and 1G
respectively)) are per process, and since I have maintenance work_mem
set at 512M (this all on a 3G box) I am not sure how it fails to
allocate the memory; although top reports only 25-30MB free, there is
some 2.5G in Inactive so there is plenty of memory available. I am
currently running memtest to see if I may have flaky RAM ...

Sven