use strict;
use DBI;
use Data::Dumper;

my $dbh = DBI->connect(..., { RaiseError => 1, PrintError => 0 });
my $sql = <<SQL;

    SELECT * FROM mytable

SQL

my $sth = $dbh->prepare($sql);
my $res = $sth->fetchall_arrayref({ Slice => {} });
print Dumper $res;