Pure perl multi-level hash/array DBM that supports transactionshttp://search.cpan.org/dist/DBM-Deep/
A unique flat-file database module, written in pure perl. True multi-level
hash/array support (unlike MLDBM, which is faked), hybrid OO / tie()
interface, cross-platform FTPable files, ACID transactions, and is quite
fast. Can handle millions of keys and unlimited levels without significant
slow-down. Written from the ground-up in pure perl -- this is NOT a
wrapper around a C-based DBM. Out-of-the-box compatibility with Unix, Mac
OS X and Windows.