I don't know much about DBM and MLDBM files but I do know a few methods other methods for persistant data structures.

• Data::Dumper - This module generates a string representation of your data structure like your one above which you can write to a text file and restore with require or eval.
• Storable - This module serializes your data structure making a binary representation of it and includes functions for storing and retriving from files. It has the advantage over Data::Dumper in that its stored structures use much less disk space.
• XML::Dumper - This module produces a XML representation of your stucture but since it uses elements such as <HASH> and <ARRAY> it doesn't make much sense from a non-perl perspective.
• XML::Simple - This module produces a file like XML::Dumper but doesn't use perl conventions/identities/names.

You may want to research these a bit more, but any of them will probably suit most needs with a minimum of hassle.
There are probably more than I can't think of at the moment as well.