This is an interface to BerkeleyDB (2.x or 3.x) that uses the native API instead of the DB1.85 API used by DB_File.

The reason I think it's relevant is that you can use a "Recno" format database, and tie it to an array. (However, the documenation is unclear on this, and I haven't got the module installed to hand).

Here is an extract from an example in the documentation:

use strict;
use BerkeleyDB;
my $filename = "text" ;
unlink $filename ;
my @h ;
tie @h, 'BerkeleyDB::Recno',
 -filename   => $filename,
 -Flags      => DB_CREATE,
 -Property   => DB_RENUMBER
   or die "Cannot open $filename: $!\n" ;


# Add a few key/value pairs to the file
$h[0] = "orange" ;
$h[1] = "blue" ;
$h[2] = "yellow" ;
push @h, "green", "black" ;
[download]

The problem then becomes if you can actually use MLDBM to tie an array instead of a hash, and TBH I don't know.

But I would have thought it would be fairly easy to add such functionality to MLDBM if it isn't there.