pg_dump chews up all system memory

To backup the postgres database on one of our
servers, we use pg_dump to dump the table to
a file. Now, we have a table that has around
300,000 records (iirc) but when pg_dump tries
to dump it, its size (in ps) grows to 270M
and the machine swaps like mad.

This is surely an error. I've temporarily fixed
it by adding another 128M swapfile (it was running
out completely and had to be rebooted) but I'd
really like to see pg_dump not use that much
memory in the first place.

Maybe it's fixed in newer versions?
--
Martijn van Oosterhout <kleptog(at)cupid(dot)suninternet(dot)com>