Upgrading MySQL strategies

[Doug Poland]

Hello,

Does someone have a strategy for upgrading MySQL?  For example, I'm 
currently running 5.2.1-RELEASE with mysql-server-4.1.1_2.  The current 
MySQL version is 4.1.2.  If I simply run portupgrade, will the new MySQL 
  binary be "OK" with the older-style database files?   If I were to 
dump the 4.1.1 files then restore, there may have been changes in the 
schema that could make this problematic.

I've searched the archives and have turned up nothing useful.  One would 
think this would be covered in MySQL's excellent on-line docs, but I 
could find no mention of upgrading.

Thanks for your help.

-- 
Regards,
Doug