Merge

2 files changed, 60 insertions, 6 deletions

diff --git a/sql/opt_subselect.cc b/sql/opt_subselect.cc
index 47771a10ae7..ec56994f16a 100644
--- a/sql/opt_subselect.cc
+++ b/sql/opt_subselect.cc
@@ -1921,11 +1921,25 @@ int pull_out_semijoin_tables(JOIN *join)
       }
     }
     
-    
     table_map pulled_tables= 0;
+    table_map dep_tables= 0;
     if (have_join_nest_children)
       goto skip;
 
+    /*
+      Calculate set of tables within this semi-join nest that have
+      other dependent tables
+    */
+    child_li.rewind();
+    while ((tbl= child_li++))
+    {
+      TABLE *const table= tbl->table;
+      if (table &&
+         (table->reginfo.join_tab->dependent &
+          sj_nest->nested_join->used_tables))
+        dep_tables|= table->reginfo.join_tab->dependent;
+    }
+
     /* Action #1: Mark the constant tables to be pulled out */
     child_li.rewind();
     while ((tbl= child_li++))
@@ -1976,7 +1990,8 @@ int pull_out_semijoin_tables(JOIN *join)
       child_li.rewind();
       while ((tbl= child_li++))
       {
-        if (tbl->table && !(pulled_tables & tbl->table->map))
+        if (tbl->table && !(pulled_tables & tbl->table->map) &&
+            !(dep_tables & tbl->table->map))
         {
           if (find_eq_ref_candidate(tbl->table, 
                                     sj_nest->nested_join->used_tables & 
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index cd81b41d0ec..d7a672b210f 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -241,7 +241,8 @@ static ORDER *create_distinct_group(THD *thd, Item **ref_pointer_array,
                                     List<Item> &all_fields,
 				    bool *all_order_by_fields_used);
 static bool test_if_subpart(ORDER *a,ORDER *b);
-static TABLE *get_sort_by_table(ORDER *a,ORDER *b,List<TABLE_LIST> &tables);
+static TABLE *get_sort_by_table(ORDER *a,ORDER *b,List<TABLE_LIST> &tables, 
+                                table_map const_tables);
 static void calc_group_buffer(JOIN *join,ORDER *group);
 static bool make_group_fields(JOIN *main_join, JOIN *curr_join);
 static bool alloc_group_fields(JOIN *join,ORDER *group);
@@ -1211,7 +1212,8 @@ JOIN::optimize()
     goto setup_subq_exit;
   }
   error= -1;					// Error is sent to client
-  sort_by_table= get_sort_by_table(order, group_list, select_lex->leaf_tables);
+  /* get_sort_by_table() call used to be here: */
+  MEM_UNDEFINED(&sort_by_table, sizeof(sort_by_table));
 
   /* Calculate how to do the join */
   thd_proc_info(thd, "statistics");
@@ -3583,6 +3585,9 @@ make_join_statistics(JOIN *join, List<TABLE_LIST> &tables_list,
     }
   } while (join->const_table_map & found_ref && ref_changed);
  
+  join->sort_by_table= get_sort_by_table(join->order, join->group_list,
+                                         join->select_lex->leaf_tables,
+                                         join->const_table_map);
   /* 
     Update info on indexes that can be used for search lookups as
     reading const tables may has added new sargable predicates. 
@@ -10284,7 +10289,23 @@ make_join_readinfo(JOIN *join, ulonglong options, uint no_jbuf_after)
                               join->group_list ?
 			       join->join_tab+join->const_tables :
                                join->get_sort_by_join_tab();
-     if (sort_by_tab)
+      /*
+        It could be that sort_by_tab==NULL, and the plan is to use filesort()
+        on the first table.
+      */
+      if (join->order)
+      {
+        join->simple_order= 0;
+        join->need_tmp= 1;
+      }
+
+      if (join->group && !join->group_optimized_away)
+      {
+        join->need_tmp= 1;
+        join->simple_group= 0;
+      }
+      
+      if (sort_by_tab)
       {
         join->need_tmp= 1;
         join->simple_order= join->simple_group= 0;
@@ -20714,7 +20735,8 @@ test_if_subpart(ORDER *a,ORDER *b)
 */
 
 static TABLE *
-get_sort_by_table(ORDER *a,ORDER *b, List<TABLE_LIST> &tables)
+get_sort_by_table(ORDER *a,ORDER *b, List<TABLE_LIST> &tables, 
+                  table_map const_tables)
 {
   TABLE_LIST *table;
   List_iterator<TABLE_LIST> ti(tables);
@@ -20728,6 +20750,23 @@ get_sort_by_table(ORDER *a,ORDER *b, List<TABLE_LIST> &tables)
 
   for (; a && b; a=a->next,b=b->next)
   {
+    /* Skip elements of a that are constant */
+    while (!((*a->item)->used_tables() & ~const_tables))
+    {
+      if (!(a= a->next))
+        break;
+    }
+
+    /* Skip elements of b that are constant */
+    while (!((*b->item)->used_tables() & ~const_tables))
+    {
+      if (!(b= b->next))
+        break;
+    }
+
+    if (!a || !b)
+      break;
+
     if (!(*a->item)->eq(*b->item,1))
       DBUG_RETURN(0);
     map|=a->item[0]->used_tables();