problems with memory

Hi,

We are running postgres-6.5.3 on a dual pentium 300 machine, 0.5Gb RAM under
Linux Redhat 6.0 (kernel 2.2.14). The machine we are using sits on a 100Mb
network and the nics are 3com3c590's. We are also using a DPT Raid
controller in a raid5 configuration set up as 1 logical drive.

We are try to insert a large amount of data into the database. What happens
is that when we first start loading data everything is fine. Over a period
of time (1.5hrs) there is a marked decrease in performance in terms of both
memory and cpu usage. At this time cpu usage has crept up to 45-50% and
memory usage is 100Mb and rising slowly and there is only one connection to
the database.

All the statistics are gleaned from using 'top'.


Consequently, the database gets slower and slower until it loads at the rate
of <3KBps at which point it becomes more exciting to watch paint dry 8-)).

Postgres is the only program running (except for normal system programs)
that uses a significant amount of memory.

Is Postgres known to leak memory? What causes the high cpu usage?

Any ideas would be greatly appreciated.

Dean