Perl query

my $messages = $c->model('Database::Messages')->search({-or => [
                            {-and => ['me.source' => $uid, -or => ['me.is_system' => 0, 'me.is_system' => undef]]},
                            'me.target' => $uid
                        ]
                        },
        {
        select => [\['DISTINCT ON(me.thread) me.thread'], qw/me.id me.source me.target me.date me.title me.text me.car me.transaction me.payment me.is_read/],
        prefetch => ['source_linked', 'target_linked', 'car_linked', 'payment_linked', 'transaction_linked'],
        as => [qw/me.thread me.id me.source me.target me.date me.title me.text me.car me.transaction me.payment me.is_read/],
        page => $page, rows => $rows
        });