Postgres Connections Requiring Large Amounts of Memory

PostgreSQL Version: 7.2.3
OS : Red Hat 7.3 with Kernel 2.4.18-5 and SGI_XFS

I currently have two processes which create several persistent
connections to the database. One process primarily does inserts and the
other primarily does selects. Both processes run 24/7.

My problem is that the memory used by the connections appears to grow
over time, especially when the amount of data entering the system is
increased. The connections sometimes take up wards of 450 MB of memory
causing other applications on the system to swap.

Is there anyway to limit the amount of memory used by a given connection
or is there something I may be doing that is requiring the connection to
need more memory?

-Dawn