It occurred to me that Geert Hendrickx wrote in gmane.os.netbsd.devel.packages:
> On Wed, Mar 30, 2005 at 09:11:19AM +0000, Martijn van Buul wrote:
>> It occurred to me that Johnny C. Lam wrote in gmane.os.netbsd.devel.packages:
>> > I completely agree with you here.  This is why I suspected I may have to 
>> > push this type of script into the packages that use db4 instead, e.g. 
>> > cyrus-sasl2 (/usr/pkg/etc/sasldb), postfix (hash: maptype), cyrus-imapd 
>> > (/var/imap and /var/spool/imap mailboxes), etc.
>> 
>> Running the risk of suggesting something perpetually stupid here:
>> 
>> Would it be possible to teach these packages how to backup and restore their
>> databases? 
>
> No, because, as said, these databases could be anywhere on the
> filesystem, not in a central place like with most SQL servers.  

I understand that db4 doesn't know where its databases are hiding - but from
the examples given above, I'm under the impression that the packages 
*using* these databases do. db4 doesn't know where cyrus-sasl2 keeps
its database. But syrus-sasl2 could know that it's in /usr/pkg/etc/sasldb.