BerkeleyDB is one of the most famous flat/non-relational databases widely used. Depending on the very strong features offerred, one can implement fast cache, in-memory/embedded database, btree, queue and vice versa. Smart guys from both sleepycat and open-source world are working very hard to bring new wonderful stuff.
Here you are touching another great feature of BerkeleyDB - Secondary Indicies. One can create several secondary databases for index purpose.
Refer to pod in module itself for more detail.
INSTALLATION
To install this module type the following:
perl Makefile.PL
make
make test
make install
DEPENDENCIES
This module requires these other modules and libraries:
BerkeleyDB YAML Storable
File::Temp (testing code)
COPYRIGHT AND LICENCE
Copyright (C) 2006 by Dongxu Ma
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.