MDL-21249 improved php docs and adding direct access prevention in dml

lib/dml/pgsql_native_moodle_temptables.php

@@ -20,12 +20,14 @@
  * are named differently than normal tables. Also used to be able to retrieve
  * temp table names included in the get_tables() method of the DB.
  *
- * @package    moodlecore
- * @subpackage DML
+ * @package    code
+ * @subpackage dml
  * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once($CFG->libdir.'/dml/moodle_temptables.php');
 
 class pgsql_native_moodle_temptables extends moodle_temptables {