1 files changed, 34 insertions, 9 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 29a78cb31dc..2a2fe3eb36f 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1523,6 +1523,15 @@ JOIN::optimize()
     if (order)
     {
       /*
+        Do we need a temporary table due to the ORDER BY not being equal to
+        the GROUP BY? The call to test_if_skip_sort_order above tests for the
+        GROUP BY clause only and hence is not valid in this case. So the
+        estimated number of rows to be read from the first table is not valid.
+        We clear it here so that it doesn't show up in EXPLAIN.
+       */
+      if (need_tmp && (select_options & SELECT_DESCRIBE) != 0)
+        join_tab[const_tables].limit= 0;
+      /*
         Force using of tmp table if sorting by a SP or UDF function due to
         their expensive and probably non-deterministic nature.
       */
@@ -2402,13 +2411,8 @@ JOIN::destroy()
 
   cleanup(1);
  /* Cleanup items referencing temporary table columns */
-  if (!tmp_all_fields3.is_empty())
-  {
-    List_iterator_fast<Item> it(tmp_all_fields3);
-    Item *item;
-    while ((item= it++))
-      item->cleanup();
-  }
+  cleanup_item_list(tmp_all_fields1);
+  cleanup_item_list(tmp_all_fields3);
   if (exec_tmp_table1)
     free_tmp_table(thd, exec_tmp_table1);
   if (exec_tmp_table2)
@@ -2419,6 +2423,19 @@ JOIN::destroy()
   DBUG_RETURN(error);
 }
 
+
+void JOIN::cleanup_item_list(List<Item> &items) const
+{
+  if (!items.is_empty())
+  {
+    List_iterator_fast<Item> it(items);
+    Item *item;
+    while ((item= it++))
+      item->cleanup();
+  }
+}
+
+
 /**
   An entry point to single-unit select (a select without UNION).
 
@@ -9008,10 +9025,10 @@ simplify_joins(JOIN *join, List<TABLE_LIST> *join_list, COND *conds, bool top)
     
   /* Flatten nested joins that can be flattened. */
   TABLE_LIST *right_neighbor= NULL;
-  bool fix_name_res= FALSE;
   li.rewind();
   while ((table= li++))
   {
+    bool fix_name_res= FALSE;
     nested_join= table->nested_join;
     if (nested_join && !table->on_expr)
     {
@@ -16696,7 +16713,15 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
         if (tab->select && tab->select->quick)
           examined_rows= tab->select->quick->records;
         else if (tab->type == JT_NEXT || tab->type == JT_ALL)
-          examined_rows= tab->limit ? tab->limit : tab->table->file->records();
+        {
+          if (tab->limit)
+            examined_rows= tab->limit;
+          else
+          {
+            tab->table->file->info(HA_STATUS_VARIABLE);
+            examined_rows= tab->table->file->stats.records;
+          }
+        }
         else
           examined_rows=(ha_rows)join->best_positions[i].records_read;