Memory exhausted in AllocSetAlloc()

Folks,

During the last database load, our database under 6.5.1
grew from about 40Gb to 62Gb.  This database consists
of one table, "psc".  The simple query 

   select count(*) from psc;

gives me the following in the log:

------------------------------------------------------------   
   FATAL 1:  Memory exhausted in AllocSetAlloc()
   proc_exit(0) [#0]
   shmem_exit(0) [#0]
   exit(0)
------------------------------------------------------------   

An earlier attempt to create an index also failed:

------------------------------------------------------------   
   query: create index gcoord on psc using btree (glon, glat);
   ProcessUtility: create index gcoord on psc using btree (glon, glat);
   /usr/lib/postgresql/bin/postmaster: reaping dead processes...
   /usr/lib/postgresql/bin/postmaster: CleanupProc: pid 15979 exited with status 11
   /usr/lib/postgresql/bin/postmaster: CleanupProc: reinitializing shared memory and semaphores
   shmem_exit(0) [#0]
   binding ShmemCreate(key=52e325, size=29679616)
------------------------------------------------------------   

Any suggestions? Have I reached limits database size limits in pgsql?

Thanks!!

--Martin


===========================================================================

Martin Weinberg                      Phone: (413) 545-3821
Dept. of Physics and Astronomy       FAX:   (413) 545-2117/0648
530 Graduate Research Tower	     weinberg@astro.umass.edu
University of Massachusetts	     http://www.astro.umass.edu/~weinberg/
Amherst, MA  01003-4525