unless ( -r "$repository_root/free/freetext.mldbm" )
       { %free_table = (); }
tie %free_table, 'MLDBM', "$repository_root/free/freetext.mldbm",
  O_CREAT | O_RDWR, 0640
  or die $!;

$free_table = \%free_table;
&build_data_structure_as_above(@some_params);
print( Dumper ( %free_table} );