"David Parker" <dparker@tazznetworks.com> writes:
> To my untrained eye, it doesn't look as though there is any lock
> contention here,
Me either; whatever that process is doing, it doesn't seem to be waiting
for a lock. Is it accumulating CPU time?
One way to get some info is to attach to the backend process with gdb
and get a stack trace:
gdb /path/to/postgres
attach PID
bt
quit
regards, tom lane