FATAL 1: palloc failure: memory exhausted - Mailing list pgsql-general

Hi,

My php3 interface to postgres6.4 on BSDI 3.0 intel machine says:
Warning: PostgresSQL query failed: pqReadData() -- backend closed the
channel
unexpectedly. This probably means the backend terminated abnormally before
or while
processing the request. in /usr/home/jrh/public_html/cam/cam.php3 on line
667

My logfile says:
FATAL 1:  palloc failure: memory exhausted

If I try to vacuum analyze verbose I get:
FATAL 1:  VACUUM (vc_rpfheap): BlowawayRelationBuffers returned -2
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally before or
while processing the request. We have lost the connection to the backend, so
further processing is impossible.  Terminating.

Advice? Especially about reading up on memory issues?
Thanks,
JohnH