foreach $i ($$array_ref) {

That should be @$array_ref.

if($Sort == "byname") {

== should be eq.

$DB{ $$i[0] } = [ $$i[1],$$i[2],$$i[3] ];

Good enough, but consider using arrow notation instead: $i->[0].

Anyway, the same using DBIx::Simple would be:

%DB = $db
    -> query('SELECT name, height, width, date FROM mydatabase')
    -> map_arrays( { byname => 0, bydate => 3 }->{$sort} );
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Or, if you want hashes (easier to use, but not as efficient) and have a $sortby that is 'name' or 'date' (instead of a $sort that is 'byname' or 'bydate'), you can just use:

%DB = $db
    -> query('SELECT name, height, width, date FROM mydatabase')
    -> map_arrays($sortby);
[download]