When updating from a version EQUAL TO OR OLDER than 0.3:

Just replace the dragon.pl file and the files in the www/ directory.

 

When updating from a version EQUAL TO OR OLDER than 0.2.2:

You should empty your databases as they contain incomplete data.

 

When updating from a version EQUAL TO OR OLDER than 0.2.1:

You must empty your databases.

I've done some pretty braindamaged thing in V0.2 which accounted all(!) traffic to one IP address.

You also need to do what's necessary for V0.1.

 

When updating from a version EQUAL TO OR OLDER than 0.1:

You must recreate the databases according to the Installation page.