my $database = "dbname";
my $username = "user";
my $password = "pass";
my $query = 
  "select directory_path, keyword1, keyword2, keyword3 from load_instance where rule_id = '1'";
...
my $dbh = DBI->connect( "DBI:Oracle:", $database, $username, $password );
...
$sth->prepare($query);