#!/usr/bin/perl
use strict;
use warnings;
use diagnostics;

use Data::Dumper;
$Data::Dumper::Sortkeys = 1;

my @array = qw(
               Tabelle1.Spalte1
               Tabelle1.Spalte2
               Tabelle2.Spalte3
               Tabelle3.Spalte3
               Tabelle3.Spalte2
               Tabelle1.Spalte3
               Tabelle2.Spalte1
               Tabelle2.Spalte2
               Tabelle1.Spalte4
               Tabelle3.Spalte1
              );

print Dumper \@array;

my %hoa = ();

#
# Array -> HoA
#
for (@array) {
    my ($tab, $spalt) = split /\./;
    if (exists $hoa{$tab}) {

        push @{$hoa{$tab}}, $spalt;
    }
    else {
        $hoa{$tab} = [ $spalt ];
    }
}

print Dumper \%hoa;

#
# Sortieren der Arrays:
#
for (keys %hoa) {
    $hoa{$_} = [ sort @{$hoa{$_}} ];
}

print Dumper \%hoa;