The Statemnt handle TYPE key can be used to do what I think you want to do.

my $dbh = DBI->connect(...);
my $st = $dbh->prepare('select * from ...');
$hash_ref = $st->fetchrow_hashref;

my $types = $st->{TYPE};

for my $type (@$types) {
    print "$type -- ";
    print [$dbh->type_info($type)]->[0]->{LOCAL_TYPE_NAME}, "\n";
    print "\n";
}

$st->finish();
$dbh->disconnect();
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