SYNOPSIS
use SDBM_File; # or DB_File, GDBM_File, NDBM_File, or ODBM_File
use DBM_Filter ;
$db = tie %hash, ...
$db->Filter_Push('int32');
use SDBM_File; # or DB_File, GDBM_File, NDBM_File, or ODBM_File
use DBM_Filter ;
$db = tie %hash, ...
$db->Filter_Push('int32');