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, 6 insertions, 9 deletions

diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 7e6753e9bf6..79ac2fe38a7 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -1531,7 +1531,7 @@ end:
   if (!head->no_keyread)
   {
     doing_key_read= 1;
-    head->enable_keyread();
+    head->set_keyread(true);
   }
 
   head->prepare_for_position();
@@ -10647,7 +10647,7 @@ int read_keys_and_merge_scans(THD *thd,
   if (!head->key_read)
   {
     enabled_keyread= 1;
-    head->enable_keyread();
+    head->set_keyread(true);
   }
   head->prepare_for_position();
 
@@ -10741,14 +10741,14 @@ int read_keys_and_merge_scans(THD *thd,
     index merge currently doesn't support "using index" at all
   */
   if (enabled_keyread)
-    head->disable_keyread();
+    head->set_keyread(false);
   if (init_read_record(read_record, thd, head, (SQL_SELECT*) 0, 1 , 1, TRUE))
     result= 1;
  DBUG_RETURN(result);
 
 err:
   if (enabled_keyread)
-    head->disable_keyread();
+    head->set_keyread(false);
   DBUG_RETURN(1);
 }
 
@@ -12074,9 +12074,6 @@ get_best_group_min_max(PARAM *param, SEL_TREE *tree, double read_time)
     DBUG_RETURN(NULL); /* Cannot execute with correlated conditions. */
 
   /* Check (SA1,SA4) and store the only MIN/MAX argument - the C attribute.*/
-  if (join->make_sum_func_list(join->all_fields, join->fields_list, 1))
-    DBUG_RETURN(NULL);
-
   List_iterator<Item> select_items_it(join->fields_list);
   is_agg_distinct = is_indexed_agg_distinct(join, &agg_distinct_flds);
 
@@ -13459,7 +13456,7 @@ QUICK_GROUP_MIN_MAX_SELECT::~QUICK_GROUP_MIN_MAX_SELECT()
   {
     DBUG_ASSERT(file == head->file);
     if (doing_key_read)
-      head->disable_keyread();
+      head->set_keyread(false);
     /*
       There may be a code path when the same table was first accessed by index,
       then the index is closed, and the table is scanned (order by + loose scan).
@@ -13652,7 +13649,7 @@ int QUICK_GROUP_MIN_MAX_SELECT::reset(void)
   if (!head->key_read)
   {
     doing_key_read= 1;
-    head->enable_keyread(); /* We need only the key attributes */
+    head->set_keyread(true); /* We need only the key attributes */
   }
   if ((result= file->ha_index_init(index,1)))
   {