I agree with rdfield and think that it would be worthwhile to give Storable a try. Why? because it is simple, faster than MLDBM, and you could probably write/test throwaway scripts in less than 15 minutes:

use strict;
use warnings;
use Storable qw(nstore);

my %data;
## sub that loads hash
GetData('data.txt', \%data);

## store to disk
nstore (\%data, "data.nstore");
[download]

To retrieve:

use strict;
use warnings;
use Storable qw(retrieve);

my %data = %{ retrieve("data.nstore") };
[download]

I use storable on data structures of the form data{a}{b}{c} for employee records. The flat text file is 1.5MB (5000 records), the nstored version is 3.5MB and it takes less than 2 seconds to store or retrieve. Try it and decide for yourself.

--Jim