This is the consolidated patch for mdev-8646:bb-10.2-mdev8646

"Re-factor the code for post-join operations".

The patch mainly contains the code ported from mysql-5.6 and
created for two essential architectural changes:
1. WL#5558: Resolve ORDER BY execution method at the optimization stage
2. WL#6071: Inline tmp tables into the nested loops algorithm

The first task was implemented for mysql-5.6 by Ole John Aske.
It allows to make all decisions on ORDER BY operation at the optimization
stage.

The second task implemented for mysql-5.6 by Evgeny Potemkin adds JOIN_TAB
nodes for post-join operations that require temporary tables. It allows
to execute these operations within the nested loops algorithm that used to
be used before this task only for join queries. Besides these task moves
all planning on the execution of these operations from the execution phase
to the optimization phase.

Some other re-factoring changes of mysql-5.6 were pulled in, mainly because
it was easier to pull them in than roll them back. In particular all
changes concerning Ref_ptr_array were incorporated.

The port required some changes in the MariaDB code that concerned the
functionality of EXPLAIN and ANALYZE. This was done mainly by Sergey
Petrunia.

1 files changed, 21 insertions, 7 deletions

diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 1ff3625e2db..705de724b70 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -7809,11 +7809,13 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
 	       List<Item> *sum_func_list,
 	       uint wild_num)
 {
+  if (!wild_num)
+    return(0);
+
   Item *item;
   List_iterator<Item> it(fields);
   Query_arena *arena, backup;
   DBUG_ENTER("setup_wild");
-  DBUG_ASSERT(wild_num != 0);
 
   /*
     Don't use arena if we are not in prepared statements or stored procedures
@@ -7892,7 +7894,7 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
 ** Check that all given fields exists and fill struct with current data
 ****************************************************************************/
 
-bool setup_fields(THD *thd, Item **ref_pointer_array,
+bool setup_fields(THD *thd, Ref_ptr_array ref_pointer_array,
                   List<Item> &fields, enum_mark_columns mark_used_columns,
                   List<Item> *sum_func_list, bool allow_sum_func)
 {
@@ -7924,8 +7926,11 @@ bool setup_fields(THD *thd, Item **ref_pointer_array,
     TODO: remove it when (if) we made one list for allfields and
     ref_pointer_array
   */
-  if (ref_pointer_array)
-    bzero(ref_pointer_array, sizeof(Item *) * fields.elements);
+  if (!ref_pointer_array.is_null())
+  {
+    DBUG_ASSERT(ref_pointer_array.size() >= fields.elements);
+    memset(ref_pointer_array.array(), 0, sizeof(Item *) * fields.elements);
+  }
 
   /*
     We call set_entry() there (before fix_fields() of the whole list of field
@@ -7943,7 +7948,7 @@ bool setup_fields(THD *thd, Item **ref_pointer_array,
   while ((var= li++))
     var->set_entry(thd, FALSE);
 
-  Item **ref= ref_pointer_array;
+  Ref_ptr_array ref= ref_pointer_array;
   thd->lex->current_select->cur_pos_in_select_list= 0;
   while ((item= it++))
   {
@@ -7956,12 +7961,16 @@ bool setup_fields(THD *thd, Item **ref_pointer_array,
       DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
       DBUG_RETURN(TRUE); /* purecov: inspected */
     }
-    if (ref)
-      *(ref++)= item;
+    if (!ref.is_null())
+    {
+      ref[0]= item;
+      ref.pop_front();
+    }
     if (item->with_sum_func && item->type() != Item::SUM_FUNC_ITEM &&
 	sum_func_list)
       item->split_sum_func(thd, ref_pointer_array, *sum_func_list,
                            SPLIT_SUM_SELECT);
+    thd->lex->current_select->select_list_tables|= item->used_tables();
     thd->lex->used_tables|= item->used_tables();
     thd->lex->current_select->cur_pos_in_select_list++;
   }
@@ -8380,7 +8389,10 @@ insert_fields(THD *thd, Name_resolution_context *context, const char *db_name,
       views and natural joins this update is performed inside the loop below.
     */
     if (table)
+    {
       thd->lex->used_tables|= table->map;
+      thd->lex->current_select->select_list_tables|= table->map;
+    }
 
     /*
       Initialize a generic field iterator for the current table reference.
@@ -8472,6 +8484,8 @@ insert_fields(THD *thd, Name_resolution_context *context, const char *db_name,
           if (field_table)
           {
             thd->lex->used_tables|= field_table->map;
+            thd->lex->current_select->select_list_tables|=
+              field_table->map;
             field_table->covering_keys.intersect(field->part_of_key);
             field_table->merge_keys.merge(field->part_of_key);
             field_table->used_fields++;