use DBI;
my $dbh=DBI->connect('dbi:Pg:dbname=test1');
$dbh->do('CREATE TABLE x (id INT)');
my $results1 = $dbh->selectall_arrayref('SELECT * FROM x WHERE 1=0');
my $results2 = $dbh->selectall_arrayref('SELECT MIN(id) FROM x WHERE 1=0');
use Data::Dumper;
print Dumper $results1;
print Dumper $results2;

##</code><code>##

$VAR1 = [];
$VAR1 = [
          [
            undef
          ]
        ];