It occurred to me that Geert Hendrickx wrote in gmane.os.netbsd.devel.packages:
> Another argument is that I wouldn't like important databases to be
> dump-restored with incompatible versions of db4 in an automated way.  
> I wouldn't mind taking some time to do that manually. :-)  

Well, maybe I shouldn't have implied an automagic backup - I'm just thinking
out loud, figuring out a way how to make that manual backup somewhat 
less painful.

For the average user, most db4 usage is in dependencies. It would be really
great if I could retrieve a list of known, system-wide db4 databases. 

(And it would be even better if db4 was backwards compatible, but I guess
 I'm preaching to the converted ;)