plpgsql function running long, but resources consumption is very low

Hi,

I'm having serious performance problems with my two plpgsql functions
(lots of calculations inside, including distance (lat,long) using
earthdistance etc).

My problem is: both functions are executing for hours (if not days) but
resource consumption is low (I/O, CPU, memory), like 2-5% only. I'm a
bit confused on what's going on there... locks? poor resources
management by Windows? I'm not really sure where the bottleneck might be.

Any hints/recommendations where and how should I look for improvements?

I'm running 8.2 on WinXP.

I'm aware it's kind of hard to say without seeing function's body, but I
thought I can give a try anyway.

Regards,
foo