Use db_select instead of db_query in the loop

gistfile1.diff

@@ -45,10 +46,17 @@ function pp_frontpage_most_content_type_render($subtype, $conf, $panel_args, $co
   );
   $table_header = array(t('user'), t('counter'));
   foreach ($types as $title => $data_type) {
-    $query_results = db_query($query, array(
-      ':type' => $data_type,
-      ':timestamp' => $last_thee_months,
-    ))->fetchAllKeyed();
+    $query = db_select('ppgetstat', 'ppst');
+    $query->rightJoin('field_data_field_user_id', 'fuid', 'fuid.field_user_id_value = ppst.doid');
+    $query->addExpression('SUM(ppst.items)', 'counter');
+    $query_results = $query->fields('ppst', array('doid'))
+      ->condition('ppst.type', $data_type)
+      ->condition('ppst.timestamp', $last_thee_months, '>')
+      ->groupBy('ppst.doid')
+      ->orderBy('counter', 'DESC')
+      ->range(0, 5)
+      ->execute()
+      ->fetchAllKeyed();

     $table_data = array();
     foreach ($query_results as $doid => $counter) {