Merge with MySQL 5.1.52

1 files changed, 28 insertions, 11 deletions

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index f06f698ae1f..65c76c0792f 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1472,6 +1472,15 @@ 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.
       */
@@ -11433,22 +11442,22 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
   if (error == NESTED_LOOP_NO_MORE_ROWS)
     error= NESTED_LOOP_OK;
 
+  if (table == NULL)                      	// If sending data to client
+  {
+    /*
+      The following will unlock all cursors if the command wasn't an
+      update command
+    */
+    join->join_free();                          // Unlock all cursors
+  }
   if (error == NESTED_LOOP_OK)
   {
     /*
       Sic: this branch works even if rc != 0, e.g. when
       send_data above returns an error.
     */
-    if (!table)					// If sending data to client
-    {
-      /*
-	The following will unlock all cursors if the command wasn't an
-	update command
-      */
-      join->join_free();			// Unlock all cursors
-      if (join->result->send_eof())
-	rc= 1;                                  // Don't send error
-    }
+    if (table == NULL && join->result->send_eof()) // If sending data to client
+      rc= 1;                                  // Don't send error 
     DBUG_PRINT("info",("%ld records output", (long) join->send_records));
   }
   else
@@ -17008,7 +17017,15 @@ 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;