And here's how you can use a database to find out: 
#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use DBI;

my @servers = (
    { Host => 'server02', GroupName => 'serversA' },
    { Host => 'server04', GroupName => 'serversA' },
    { Host => 'server02', GroupName => 'serversB' },
    { Host => 'server04', GroupName => 'serversB' },
    { Host => 'server02', GroupName => 'serversC' },
    { Host => 'server04', GroupName => 'serversC' },
    { Host => 'server02', GroupName => 'serversD' },
);

my $db = DBI->connect('dbi:SQLite:dbname=:memory:', "", "");
$db->do('CREATE TABLE servers (host TEXT, group_name TEXT)');
my $populate = $db->prepare('INSERT INTO servers VALUES(?, ?)');
$populate->execute($_->{Host}, $_->{GroupName}) for @servers;

my $query = $db->prepare('SELECT host, GROUP_CONCAT(group_name) FROM s
+ervers GROUP BY host');
$query->execute;
while (my @row = $query->fetchrow_array) {
    say "@row";
}

[download]
map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re: Array consolidating values by choroba
in thread Array consolidating values by maikelnight

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