backend cpu usage? [7.2]

[postgresql-7.2, x86 linux]
How can I get cpu usage info in 7.2 about the backend process of my db
connection?  I tried looking at the pg_stat_get_backend_pid function
but it requires a backend_id that I don't know how to get.

If I can get the backend pid I can fork a 'ps' command from my app,
though it would be nicer to get it directly through sql.

-- George Young

-- I cannot think why the whole bed of the ocean isnot one solid mass of oysters, so prolific they seem. Ah,I am
wandering!Strange how the brain controls the brain!-- Sherlock Holmes in "The Dying Detective"