Upgrading memory and swap partition / pagefile

As you maybe can tell from the thread title, I've no idea how this works in OSX!

In OSX, if you upgrade the memory, does the machine intelligently alter the pagefile or swapfile or whatever is the equivalent in BSD style OS's?

XP for instance would dynamically resize the pagefile (if set), and linux you'd probably end up creating a new swap partition. Do either of these need to be followed for OSX?

Thanks for any help.