mac ports question

I ran into a problem today where somewhere my port of postgresql82 just
stopped working.  I'm largely an idiot on Mac because I use is as a
workstation/development box and do most of the real system related work
on my debian boxes.

But I don't know how to get the port working again.

Then I saw there is a new version 8.3 in port.

So, if I upgrade does anyone know if this cleanly removes version 8.2
from the box so I don't have to start carrying multiple versions?

I don't really need to upgrade, but I figured it would be an easy way to
get my database running again and get me back up to current toys.  Of
course, upgrades don't often work out that well...