Issue #3200123 by PROMES, JeroenT: Make purging more efficient

      // Get the records elegible for purging.

      $limit = variable_get('webform_purge_cron_limit', 100000);

      if ($purge_all == 1) {

        $query = db_query('SELECT * FROM {webform_submissions} WHERE submitted < :purge_timestamp' . ($limit ? ' LIMIT ' . check_plain($limit) : ''), array(':purge_timestamp' => $purge_timestamp));

        $query = db_query('SELECT nid, sid FROM {webform_submissions} WHERE submitted < :purge_timestamp ORDER BY nid' . ($limit ? ' LIMIT ' . check_plain($limit) : ''), array(':purge_timestamp' => $purge_timestamp));

      }

      else {

        $query = db_query('SELECT * FROM {webform_submissions} WHERE submitted < :purge_timestamp AND nid IN (:nid)' . ($limit ? ' LIMIT ' . check_plain($limit) : ''), array(':purge_timestamp' => $purge_timestamp, ':nid' => $checkboxes));

        $query = db_query('SELECT nid, sid FROM {webform_submissions} WHERE submitted < :purge_timestamp AND nid IN (:nid) ORDER BY nid' . ($limit ? ' LIMIT ' . check_plain($limit) : ''), array(':purge_timestamp' => $purge_timestamp, ':nid' => $checkboxes));

      }

      $rows = $query->fetchAll();

      // If submissions found to purge, get on with it.

      if (count($rows) > 0) {

        $deleted = 0;

        $deleted = $nid = 0;

        foreach ($rows as $row) {

          // Results are sorted by the node ID. When the node ID is the same,

          // don't load the node again from the database.

          if ($row->nid != $nid) {

            $node = node_load($row->nid);

            $nid = $row->nid;

          }

          $submission = webform_menu_submission_load($row->sid, $row->nid);

          webform_submission_delete($node, $submission);

          $deleted++;