Post-merge fixes for rocksdb.group_min_max test

- Fix the LooseScan code to support storage engines that return
  HA_ERR_END_OF_FILE if the index scan goes out of provided range
  bounds
- Add a DBUG_EXECUTE_IF("force_group_by",...) to allow a test to
  force a LooseScan
- Adjust rocksdb.group_min_max test not to use features not present
  in MariaDB 10.2 (e.g. optimizer_trace.  In MariaDB 10.4 it's present
  but it doesn't meet the  assumptions that the test makes about it
- Adjust the test result file:
  = MariaDB doesn't support "Enhanced Loose Scan" that FB/MySQL has
  = MariaDB has different cost calculations.

sql/opt_range.cc

@@ -2428,6 +2428,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     KEY_PART *key_parts;
     KEY *key_info;
     PARAM param;
+    bool force_group_by = false;
 
     if (check_stack_overrun(thd, 2*STACK_MIN_SIZE + sizeof(PARAM), buff))
       DBUG_RETURN(0);                           // Fatal error flag is set
@@ -2555,15 +2556,20 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
       Try to construct a QUICK_GROUP_MIN_MAX_SELECT.
       Notice that it can be constructed no matter if there is a range tree.
     */
+    DBUG_EXECUTE_IF("force_group_by", force_group_by = true; );
     group_trp= get_best_group_min_max(&param, tree, best_read_time);
     if (group_trp)
     {
       param.table->quick_condition_rows= MY_MIN(group_trp->records,
                                              head->stat_records());
-      if (group_trp->read_cost < best_read_time)
+      if (group_trp->read_cost < best_read_time || force_group_by)
       {
         best_trp= group_trp;
         best_read_time= best_trp->read_cost;
+        if (force_group_by)
+        {
+          goto force_plan;
+        }
       }
     }
 
@@ -2663,6 +2669,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
       }
     }
 
+force_plan:
     thd->mem_root= param.old_root;
 
     /* If we got a read plan, create a quick select from it. */
@@ -11509,14 +11516,29 @@ int QUICK_RANGE_SELECT::get_next_prefix(uint prefix_length,
       DBUG_ASSERT(cur_prefix != NULL);
       result= file->ha_index_read_map(record, cur_prefix, keypart_map,
                                       HA_READ_AFTER_KEY);
-      if (result || last_range->max_keypart_map == 0)
+      if (result || last_range->max_keypart_map == 0) {
+        /*
+          Only return if actual failure occurred. For HA_ERR_KEY_NOT_FOUND
+          or HA_ERR_END_OF_FILE, we just want to continue to reach the next
+          set of ranges. It is possible for the storage engine to return
+          HA_ERR_KEY_NOT_FOUND/HA_ERR_END_OF_FILE even when there are more
+          keys if it respects the end range set by the read_range_first call
+          below.
+        */
+        if (result != HA_ERR_KEY_NOT_FOUND && result != HA_ERR_END_OF_FILE)
           DBUG_RETURN(result);
-
+      } else {
+        /*
+          For storage engines that don't respect end range, check if we've
+          moved past the current range.
+        */
         key_range previous_endpoint;
-      last_range->make_max_endpoint(&previous_endpoint, prefix_length, keypart_map);
+        last_range->make_max_endpoint(&previous_endpoint, prefix_length,
+                                      keypart_map);
         if (file->compare_key(&previous_endpoint) <= 0)
           DBUG_RETURN(0);
       }
+    }
 
     uint count= ranges.elements - (uint)(cur_range - (QUICK_RANGE**) ranges.buffer);
     if (count == 0)

storage/rocksdb/mysql-test/rocksdb/include/group_min_max.inc

@@ -266,6 +266,17 @@ select a1,  max(c)           from t2 where a1 in ('a','b','d') group by a1,a2,b;
 
 # B) Equalities only over the non-group 'B' attributes
 # plans
+--echo #
+--echo # MariaDB: we dont have the following patch:
+--echo #
+--echo #  commit 60a92a79a3b7fde3c6efe91799e344b977c8e5c3
+--echo #  Author: Manuel Ung <mung@fb.com>
+--echo #  Date:   Thu Apr 19 23:06:27 2018 -0700
+--echo #
+--echo #   Enhance group-by loose index scan
+--echo #
+--echo #  So the following results are not very meaningful, but are still kept here
+
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
@@ -730,9 +741,9 @@ explain extended select a1,a2,count(a2) from t1 where (a1 > 'a') group by a1,a2,
 explain extended select sum(ord(a1)) from t1 where (a1 > 'a') group by a1,a2,b;
 
 # test multi_range_groupby flag
-set optimizer_switch = 'multi_range_groupby=off';
+#MariaDB: no support: set optimizer_switch = 'multi_range_groupby=off';
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
-set optimizer_switch = 'default';
+#set optimizer_switch = 'default';
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
 
 
@@ -1361,41 +1372,41 @@ drop table t1;
 eval CREATE TABLE t (a INT, b INT, KEY(a,b)) engine=$engine;
 INSERT INTO t VALUES (1,1), (2,2), (3,3), (4,4), (1,0), (3,2), (4,5);
 ANALYZE TABLE t;
-let $DEFAULT_TRACE_MEM_SIZE=1048576; # 1MB
-eval set optimizer_trace_max_mem_size=$DEFAULT_TRACE_MEM_SIZE;
-set @@session.optimizer_trace='enabled=on';
-set end_markers_in_json=on;
+# MariaDB: 10.2 doesn't have trace, yet: let $DEFAULT_TRACE_MEM_SIZE=1048576; # 1MB
+# eval set optimizer_trace_max_mem_size=$DEFAULT_TRACE_MEM_SIZE;
+# set @@session.optimizer_trace='enabled=on';
+# set end_markers_in_json=on;
 
 ANALYZE TABLE t;
 
 SELECT a, SUM(DISTINCT a), MIN(b) FROM t GROUP BY a;
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b) FROM t GROUP BY a;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
 EXPLAIN SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
 EXPLAIN SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
 EXPLAIN SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
 SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
+#SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
+#  FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
 
-SET optimizer_trace_max_mem_size=DEFAULT;
-SET optimizer_trace=DEFAULT;
-SET end_markers_in_json=DEFAULT;
+#SET optimizer_trace_max_mem_size=DEFAULT;
+#SET optimizer_trace=DEFAULT;
+#SET end_markers_in_json=DEFAULT;
 
 DROP TABLE t;
 

storage/rocksdb/mysql-test/rocksdb/r/group_min_max.result

-set global debug="+d,force_group_by";
+set @debug_tmp= @@debug_dbug;
+set global debug_dbug="+d,force_group_by";
 drop table if exists t1;
 create table t1 (
 a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(248) default ' '
@@ -134,34 +135,34 @@ Table	Op	Msg_type	Msg_text
 test.t3	analyze	status	OK
 explain select a1, min(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a1, max(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	65	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	65	NULL	63	Using index for group-by
 explain select a1, min(a2), max(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a1, a2, b, min(c), max(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t2 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	#	NULL	#	Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	#	NULL	#	Using index for group-by
 explain select min(a2), a1, max(a2), min(a2), a1 from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a1, b, min(c), a1, max(c), b, a2, max(c), max(c) from t1 group by a1, a2, b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select min(a2) from t1 group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using index for group-by
 explain select a2, min(c), max(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 select a1, min(a2) from t1 group by a1;
 a1	min(a2)
 a	a
@@ -288,37 +289,37 @@ b	i421	l421
 b	m422	p422
 explain select a1,a2,b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where a1 >= 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	502	Using where; Using index for group-by
 explain select a1, max(c)            from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	502	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where a1 >= 'c' or a2 < 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1503	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	753	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1503	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	753	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	2004	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1004	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	2004	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1004	Using where; Using index for group-by
 explain select a1,min(c),max(c)      from t1 where a1 >= 'b' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,  max(c)           from t1 where a1 in ('a','b','d') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	1503	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	753	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
@@ -668,99 +669,109 @@ d	d411
 d	h412
 d	l421
 d	p422
+#
+# MariaDB: we dont have the following patch:
+#
+#  commit 60a92a79a3b7fde3c6efe91799e344b977c8e5c3
+#  Author: Manuel Ung <mung@fb.com>
+#  Date:   Thu Apr 19 23:06:27 2018 -0700
+#
+#   Enhance group-by loose index scan
+#
+#  So the following results are not very meaningful, but are still kept here
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	63	Using where; Using index for group-by
 explain select a1,max(c),min(c)      from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,       max(c) from t1 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t1 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2, max(c)         from t1 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using where; Using index for group-by
 explain select a1,a2, max(c)         from t1 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	63	Using where; Using index for group-by
 explain select a1,max(c),min(c)      from t2 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,       max(c) from t2 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t2 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2, max(c)         from t2 where (b = 'b') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	126	Using where; Using index for group-by
 explain select a1,a2, max(c)         from t2 where (b = 'b' or b = 'a') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	range	NULL	idx_t3_1	6	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	range	NULL	idx_t3_1	6	NULL	63	Using where; Using index for group-by
 explain select a1,max(c),min(c)      from t3 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 explain select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t3	range	idx_t3_0,idx_t3_1,idx_t3_2	idx_t3_1	6	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t3	index	NULL	idx_t3_1	10	NULL	1000	Using where; Using index
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
 a	a	b	h112	e112
@@ -769,22 +780,22 @@ c	a	b	h312	e312
 d	a	b	h412	e412
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	e112
-b	b	b	p222	e212
-c	b	b	p322	e312
-d	b	b	p422	e412
+a	a	b	p122	e112
+b	a	b	p222	e212
+c	a	b	p322	e312
+d	a	b	p422	e412
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	a	b	h112	a111
-b	a	b	h212	a211
-c	a	b	h312	a311
-d	a	b	h412	a411
+a	a	a	h112	a111
+b	a	a	h212	a211
+c	a	a	h312	a311
+d	a	a	h412	a411
 select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a' or a2 = 'b') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	a111
-b	b	b	p222	a211
-c	b	b	p322	a311
-d	b	b	p422	a411
+a	a	a	p122	a111
+b	a	a	p222	a211
+c	a	a	p322	a311
+d	a	a	p422	a411
 select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b') group by a1;
 a1	max(c)	min(c)
 a	h112	e112
@@ -815,14 +826,14 @@ d	a	b	h412
 d	b	b	p422
 select a1,a2,b,       max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	max(c)
-a	a	b	h112
-a	b	b	p122
-b	a	b	h212
-b	b	b	p222
-c	a	b	h312
-c	b	b	p322
-d	a	b	h412
-d	b	b	p422
+a	a	a	h112
+a	b	a	p122
+b	a	a	h212
+b	b	a	p222
+c	a	a	h312
+c	b	a	p322
+d	a	a	h412
+d	b	a	p422
 select a1,a2,b,min(c),max(c) from t1 where (b = 'b') group by a1,a2;
 a1	a2	b	min(c)	max(c)
 a	a	b	e112	h112
@@ -835,14 +846,14 @@ d	a	b	e412	h412
 d	b	b	m422	p422
 select a1,a2,b,min(c),max(c) from t1 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	min(c)	max(c)
-a	a	b	a111	h112
-a	b	b	i121	p122
-b	a	b	a211	h212
-b	b	b	i221	p222
-c	a	b	a311	h312
-c	b	b	i321	p322
-d	a	b	a411	h412
-d	b	b	i421	p422
+a	a	a	a111	h112
+a	b	a	i121	p122
+b	a	a	a211	h212
+b	b	a	i221	p222
+c	a	a	a311	h312
+c	b	a	i321	p322
+d	a	a	a411	h412
+d	b	a	i421	p422
 select a1,a2, max(c)         from t1 where (b = 'b') group by a1,a2;
 a1	a2	max(c)
 a	a	h112
@@ -872,17 +883,18 @@ d	a	b	h412	e412
 e	a	b	NULL	NULL
 select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	e112
-b	b	b	p222	e212
-c	b	b	p322	e312
-d	b	b	p422	e412
+a	a	b	p122	e112
+b	a	b	p222	e212
+c	a	b	p322	e312
+d	a	b	p422	e412
+e	a	b	NULL	NULL
 select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	a	b	h112	a111
-b	a	b	h212	a211
-c	a	b	h312	a311
-d	a	b	h412	a411
-e	a	b	NULL	NULL
+a	a	a	h112	a111
+b	a	a	h212	a211
+c	a	a	h312	a311
+d	a	a	h412	a411
+e	a	a	NULL	NULL
 select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b') group by a1;
 a1	max(c)	min(c)
 a	h112	e112
@@ -896,6 +908,7 @@ a	p122	e112
 b	p222	e212
 c	p322	e312
 d	p422	e412
+e	NULL	NULL
 select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	max(c)	min(c)
 a	h112	a111
@@ -916,15 +929,15 @@ d	b	b	p422
 e	a	b	NULL
 select a1,a2,b,       max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	max(c)
-a	a	b	h112
-a	b	b	p122
-b	a	b	h212
-b	b	b	p222
-c	a	b	h312
-c	b	b	p322
-d	a	b	h412
-d	b	b	p422
-e	a	b	NULL
+a	a	a	h112
+a	b	a	p122
+b	a	a	h212
+b	b	a	p222
+c	a	a	h312
+c	b	a	p322
+d	a	a	h412
+d	b	a	p422
+e	a	a	NULL
 select a1,a2,b,min(c),max(c) from t2 where (b = 'b') group by a1,a2;
 a1	a2	b	min(c)	max(c)
 a	a	b	e112	h112
@@ -938,15 +951,15 @@ d	b	b	m422	p422
 e	a	b	NULL	NULL
 select a1,a2,b,min(c),max(c) from t2 where (b = 'b' or b = 'a') group by a1,a2;
 a1	a2	b	min(c)	max(c)
-a	a	b	a111	h112
-a	b	b	i121	p122
-b	a	b	a211	h212
-b	b	b	i221	p222
-c	a	b	a311	h312
-c	b	b	i321	p322
-d	a	b	a411	h412
-d	b	b	i421	p422
-e	a	b	NULL	NULL
+a	a	a	a111	h112
+a	b	a	i121	p122
+b	a	a	a211	h212
+b	b	a	i221	p222
+c	a	a	a311	h312
+c	b	a	i321	p322
+d	a	a	a411	h412
+d	b	a	i421	p422
+e	a	a	NULL	NULL
 select a1,a2, max(c)         from t2 where (b = 'b') group by a1,a2;
 a1	a2	max(c)
 a	a	h112
@@ -976,14 +989,14 @@ b	a	b	h212	e212
 c	a	b	h312	e312
 select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a' or a2 = 'b') and (b = 'b') group by a1;
 a1	a2	b	max(c)	min(c)
-a	b	b	p122	e112
-b	b	b	p222	e212
-c	b	b	p322	e312
+a	a	b	p122	e112
+b	a	b	p222	e212
+c	a	b	p322	e312
 select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b' or b = 'a') group by a1;
 a1	a2	b	max(c)	min(c)
-a	a	b	h112	a111
-b	a	b	h212	a211
-c	a	b	h312	a311
+a	a	a	h112	a111
+b	a	a	h212	a211
+c	a	a	h312	a311
 select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b') group by a1;
 a1	max(c)	min(c)
 a	h112	e112
@@ -1001,37 +1014,41 @@ b	h212	a211
 c	h312	a311
 explain select a1,a2,b,min(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	63	Using where; Using index for group-by
 explain select a1,a2,b,max(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c) from t2 where b is NULL group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,max(c) from t2 where b is NULL group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	126	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where b is NULL group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	126	Using where; Using index for group-by
 select a1,a2,b,min(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 a1	a2	b	min(c)
 a	a	NULL	a777
 c	a	NULL	c777
 select a1,a2,b,min(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 a1	a2	b	min(c)
+a	a	NULL	a777
+c	a	NULL	c777
 select a1,a2,b,max(c) from t2 where (a2 = 'a') and b is NULL group by a1;
 a1	a2	b	max(c)
 a	a	NULL	a999
 c	a	NULL	c999
 select a1,a2,b,max(c) from t2 where (a2 = 'a' or a2 = 'b') and b is NULL group by a1;
 a1	a2	b	max(c)
+a	a	NULL	a999
+c	a	NULL	c999
 select a1,a2,b,min(c) from t2 where b is NULL group by a1,a2;
 a1	a2	b	min(c)
 a	a	NULL	a777
@@ -1050,97 +1067,97 @@ a	a	NULL	a777	a999
 c	a	NULL	c777	c999
 explain select a1,a2,b,       max(c) from t1 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (c between 'b111' and 'g112') or (c between 'd000' and 'i110') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'f123') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'k321') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,       max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 select a1,a2,b,       max(c) from t1 where (c > 'b1') group by a1,a2,b;
 a1	a2	b	max(c)
 a	a	a	d111
@@ -1562,35 +1579,36 @@ explain select a1,a2,b,min(c),max(c) from t1
 where exists ( select * from t2 where t2.c = t1.c )
 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	index	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	Using where; Using index
-2	DEPENDENT SUBQUERY	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
+1	PRIMARY	t1	index	NULL	idx_t1_1	163	NULL	1000	Using index
+1	PRIMARY	<subquery2>	eq_ref	distinct_key	distinct_key	16	func	1	
+2	MATERIALIZED	t2	index	NULL	idx_t2_1	163	NULL	1000	Using index
 explain select a1,a2,b,min(c),max(c) from t1
 where exists ( select * from t2 where t2.c > 'b1' )
 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	PRIMARY	t1	index	NULL	idx_t1_1	163	NULL	1000	Using index
 2	SUBQUERY	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (c > 'b111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t1 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	502	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122') or (c < 'h112') or (c = 'c111')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1002	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	502	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t1 where (ord(a1) > 97) and (ord(a2) + ord(a1) > 194) and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
@@ -1599,7 +1617,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c),max(c) from t2 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,min(c) from t2 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
@@ -1695,31 +1713,31 @@ select a1,a2,b,min(c) from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') grou
 a1	a2	b	min(c)
 explain select a1,a2,b from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121' or c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select a1,a2,b from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121' or c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
@@ -1770,50 +1788,50 @@ select a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1
 a1	a2	b
 explain select distinct a1,a2,b from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain extended select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	idx_t1_1	idx_t1_1	163	NULL	1001	99.90	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	501	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select distinct `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where ((`test`.`t1`.`c` = 'i121') and (`test`.`t1`.`b` = 'a') and (`test`.`t1`.`a2` >= 'b'))
+Note	1003	select distinct `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where `test`.`t1`.`b` = 'a' and `test`.`t1`.`c` = 'i121' and `test`.`t1`.`a2` >= 'b'
 explain select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select distinct b from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	Using where; Using index
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using where; Using index
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'b';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'e';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1,a2,b from t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using index for group-by
 explain select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain extended select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t2	range	idx_t2_1	idx_t2_1	163	NULL	1001	99.90	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	501	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select distinct `test`.`t2`.`a1` AS `a1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where ((`test`.`t2`.`c` = 'i121') and (`test`.`t2`.`b` = 'a') and (`test`.`t2`.`a2` >= 'b'))
+Note	1003	select distinct `test`.`t2`.`a1` AS `a1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where `test`.`t2`.`b` = 'a' and `test`.`t2`.`c` = 'i121' and `test`.`t2`.`a2` >= 'b'
 explain select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select distinct b from t2 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_1,idx_t2_2	idx_t2_2	146	NULL	1000	Using where; Using index
+1	SIMPLE	t2	index	NULL	idx_t2_2	146	NULL	1000	Using where; Using index
 explain select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'b';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	126	Using where; Using index for group-by
 explain select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'e';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	126	Using where; Using index for group-by
 select distinct a1,a2,b from t1;
 a1	a2	b
 a	a	a
@@ -1942,40 +1960,40 @@ c	e
 d	e
 explain select distinct a1,a2,b from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using index for group-by
 explain select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	251	Using where; Using index for group-by
 explain select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select distinct b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by; Using temporary; Using filesort
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by; Using temporary; Using filesort
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'b' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1 from t1 where a1 in ('a', 'd') and a2 = 'e' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	252	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
 explain select distinct a1,a2,b from t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using index for group-by
 explain select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	#	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	idx_t2_1	163	NULL	#	Using where; Using index for group-by
 explain select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by
 explain select distinct b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_1,idx_t2_2	idx_t2_1	146	NULL	#	Using where; Using index for group-by; Using temporary; Using filesort
+1	SIMPLE	t2	range	NULL	idx_t2_1	146	NULL	#	Using where; Using index for group-by; Using temporary; Using filesort
 explain select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'b' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	129	NULL	#	Using where; Using index for group-by
@@ -2064,23 +2082,23 @@ select distinct a1 from t2 where a1 in ('a', 'd') and a2 = 'e' group by a1;
 a1
 explain select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1	idx_t1_1	163	NULL	1001	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	idx_t1_1	163	NULL	501	Using where; Using index for group-by (scanning)
 explain extended select count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	100.00	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`b` = 'c') and (`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
+Note	1003	select count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `count(distinct a1,a2,b)` from `test`.`t1` where `test`.`t1`.`b` = 'c' and `test`.`t1`.`a1` > 'a' and `test`.`t1`.`a2` > 'a'
 explain select count(distinct b) from t1 where (a2 >= 'b') and (b = 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	Using where; Using index
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using where; Using index
 explain extended select 98 + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	100.00	Using where; Using index for group-by (scanning)
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	100.00	Using where; Using index for group-by
 Warnings:
-Note	1003	/* select#1 */ select (98 + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`)) AS `98 + count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
+Note	1003	select 98 + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `98 + count(distinct a1,a2,b)` from `test`.`t1` where `test`.`t1`.`a1` > 'a' and `test`.`t1`.`a2` > 'a'
 select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
 count(distinct a1,a2,b)
 4
@@ -2098,19 +2116,19 @@ select 98 + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
 104
 explain select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(a1,min(c)),b from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(a1,min(c)),b,max(c) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(a1,a2),b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using where; Using index for group-by
 explain select concat(ord(min(b)),ord(max(b))),min(b),max(b) from t1 group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_1,idx_t1_2	idx_t1_1	147	NULL	251	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	147	NULL	126	Using index for group-by
 select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
 a1	a2	b	concat(min(c), max(c))
 a	a	a	a111d111
@@ -2179,85 +2197,83 @@ concat(ord(min(b)),ord(max(b)))	min(b)	max(b)
 9798	a	b
 explain select a1,a2,b,d,min(c),max(c) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	NULL
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	
 explain select a1,a2,b,d from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	NULL
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	
 explain extended select a1,a2,min(b),max(b) from t1
 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (c > 'a111') group by a1,a2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,min(`test`.`t1`.`b`) AS `min(b)`,max(`test`.`t1`.`b`) AS `max(b)` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`c` > 'a111')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,min(`test`.`t1`.`b`) AS `min(b)`,max(`test`.`t1`.`b`) AS `max(b)` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`c` > 'a111' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`
 explain extended select a1,a2,b,min(c),max(c) from t1
 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (d > 'xy2') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	100.00	Using where
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,min(`test`.`t1`.`c`) AS `min(c)`,max(`test`.`t1`.`c`) AS `max(c)` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`d` > 'xy2')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,min(`test`.`t1`.`c`) AS `min(c)`,max(`test`.`t1`.`c`) AS `max(c)` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`d` > 'xy2' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain extended select a1,a2,b,c from t1
 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (d > 'xy2') group by a1,a2,b,c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	100.00	Using where
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`d` > 'xy2')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`,`test`.`t1`.`c`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`d` > 'xy2' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`,`test`.`t1`.`c`
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') or (b < 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b < 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b <= 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b <= 'b' and b >= 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain extended select a1,a2,b from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (c > 'a111') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	163	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`c` > 'a111')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (`test`.`t1`.`a1` = 'b' or `test`.`t1`.`a1` = 'd' or `test`.`t1`.`a1` = 'a' or `test`.`t1`.`a1` = 'c') and `test`.`t1`.`a2` > 'a' and `test`.`t1`.`c` > 'a111' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain select a1,a2,min(b),c from t2 where (a2 = 'a') and (c = 'a111') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 select a1,a2,min(b),c from t2 where (a2 = 'a') and (c = 'a111') group by a1;
 a1	a2	min(b)	c
 a	a	a	a111
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') or (b = 'a') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,min(c),max(c) from t2
 where (c > 'a000') and (c <= 'd999') and (c like '_8__') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	1000	Using where; Using index
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1, a2, b, c, min(d), max(d) from t1 group by a1,a2,b,c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1	idx_t1_1	163	NULL	1000	NULL
+1	SIMPLE	t1	index	NULL	idx_t1_1	163	NULL	1000	
 explain select a1,a2,count(a2) from t1 group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using index
 explain extended select a1,a2,count(a2) from t1 where (a1 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,count(`test`.`t1`.`a2`) AS `count(a2)` from `test`.`t1` where (`test`.`t1`.`a1` > 'a') group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
+Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,count(`test`.`t1`.`a2`) AS `count(a2)` from `test`.`t1` where `test`.`t1`.`a1` > 'a' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain extended select sum(ord(a1)) from t1 where (a1 > 'a') group by a1,a2,b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	147	NULL	1000	100.00	Using where; Using index
 Warnings:
-Note	1003	/* select#1 */ select sum(ord(`test`.`t1`.`a1`)) AS `sum(ord(a1))` from `test`.`t1` where (`test`.`t1`.`a1` > 'a') group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
-set optimizer_switch = 'multi_range_groupby=off';
+Note	1003	select sum(ord(`test`.`t1`.`a1`)) AS `sum(ord(a1))` from `test`.`t1` where `test`.`t1`.`a1` > 'a' group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_0	65	NULL	1000	Using where
-set optimizer_switch = 'default';
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'a' or b = 'b') group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	163	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t2	index	NULL	idx_t2_1	163	NULL	1000	Using where; Using index
 explain select distinct(a1) from t1 where ord(a2) = 98;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_0	65	NULL	1000	Using where
+1	SIMPLE	t1	index	NULL	idx_t1_2	147	NULL	1000	Using where; Using index
 select distinct(a1) from t1 where ord(a2) = 98;
 a1
 a
@@ -2266,7 +2282,7 @@ c
 d
 explain select a1 from t1 where a2 = 'b' group by a1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using where; Using index for group-by
 select a1 from t1 where a2 = 'b' group by a1;
 a1
 a
@@ -2275,7 +2291,7 @@ c
 d
 explain select distinct a1 from t1 where a2 = 'b';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	130	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	idx_t1_1	130	NULL	63	Using where; Using index for group-by
 select distinct a1 from t1 where a2 = 'b';
 a1
 a
@@ -2385,7 +2401,7 @@ INSERT INTO t1 (a) VALUES
 ('SOUTH EAST'), ('SOUTH WEST'), ('WESTERN');
 EXPLAIN SELECT DISTINCT a,a FROM t1 ORDER BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	PRIMARY	PRIMARY	66	NULL	1001	Using index for group-by
+1	SIMPLE	t1	index	NULL	PRIMARY	66	NULL	1000	Using index
 SELECT DISTINCT a,a FROM t1 ORDER BY a;
 a	a
 	
@@ -2477,7 +2493,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT max(b), a FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 FLUSH STATUS;
 SELECT max(b), a FROM t1 GROUP BY a;
 max(b)	a
@@ -2489,15 +2505,17 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 EXPLAIN SELECT max(b), a FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 FLUSH STATUS;
 CREATE TABLE t2 engine=RocksDB SELECT max(b), a FROM t1 GROUP BY a;
 SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 SELECT * FROM (SELECT max(b), a FROM t1 GROUP BY a) b;
 max(b)	a
@@ -2509,6 +2527,7 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 (SELECT max(b), a FROM t1 GROUP BY a) UNION 
 (SELECT max(b), a FROM t1 GROUP BY a);
@@ -2521,50 +2540,52 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	16
 Handler_read_next	0
+Handler_read_retry	0
 EXPLAIN (SELECT max(b), a FROM t1 GROUP BY a) UNION 
 (SELECT max(b), a FROM t1 GROUP BY a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1	range	a	a	5	NULL	501	Using index for group-by
-2	UNION	t1	range	a	a	5	NULL	501	Using index for group-by
-NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	Using temporary
+1	PRIMARY	t1	range	NULL	a	5	NULL	251	Using index for group-by
+2	UNION	t1	range	NULL	a	5	NULL	251	Using index for group-by
+NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 EXPLAIN SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
 FROM t1 AS t1_outer;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE EXISTS 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+2	SUBQUERY	t1	index	NULL	a	10	NULL	1000	Using index
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using index
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
 a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer	index	NULL	a	10	NULL	1000	Using where; Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	<subquery2>	ALL	distinct_key	NULL	NULL	NULL	251	
+1	PRIMARY	t1_outer	ref	a	a	5	<subquery2>.max(b)	4	Using index
+2	MATERIALIZED	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer GROUP BY a HAVING 
 a > (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer	range	a	a	5	NULL	501	Using index for group-by
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	t1_outer	range	NULL	a	5	NULL	251	Using index for group-by
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2 
 ON t1_outer1.a = (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) 
 AND t1_outer1.b = t1_outer2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	1000	Using where; Using index
-1	PRIMARY	t1_outer1	ref	a	a	10	const,test.t1_outer2.b	1	Using where; Using index
-2	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+1	PRIMARY	t1_outer1	ref	a	a	5	const	4	Using where; Using index
+1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	1000	Using where; Using index; Using join buffer (flat, BNL join)
+2	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 EXPLAIN SELECT (SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
 FROM t1 AS t1_outer) x2 FROM t1 AS t1_outer2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	1000	Using index
 2	SUBQUERY	t1_outer	index	NULL	a	10	NULL	1000	Using index
-3	SUBQUERY	t1	range	a	a	5	NULL	501	Using index for group-by
+3	SUBQUERY	t1	range	NULL	a	5	NULL	251	Using index for group-by
 CREATE TABLE t3 LIKE t1;
 FLUSH STATUS;
 INSERT INTO t3 SELECT a,MAX(b) FROM t1 GROUP BY a;
@@ -2572,6 +2593,7 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 DELETE FROM t3;
 FLUSH STATUS;
 INSERT INTO t3 SELECT 1, (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) 
@@ -2580,12 +2602,14 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 DELETE FROM t3 WHERE (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) > 10000;
 SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	0
+Handler_read_retry	0
 FLUSH STATUS;
 DELETE FROM t3 WHERE (SELECT (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) x 
 FROM t1) > 10000;
@@ -2594,6 +2618,7 @@ SHOW STATUS LIKE 'handler_read__e%';
 Variable_name	Value
 Handler_read_key	8
 Handler_read_next	1
+Handler_read_retry	0
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a int, INDEX idx(a)) engine=RocksDB;
 INSERT INTO t1 VALUES
@@ -2604,7 +2629,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT DISTINCT(a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx	idx	5	NULL	1001	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx	5	NULL	501	Using index for group-by
 SELECT DISTINCT(a) FROM t1;
 a
 1
@@ -2612,7 +2637,7 @@ a
 4
 EXPLAIN SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	idx	idx	5	NULL	1001	Using index for group-by
+1	SIMPLE	t1	range	NULL	idx	5	NULL	501	Using index for group-by
 SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;
 a
 1
@@ -2640,7 +2665,7 @@ CREATE INDEX break_it ON t1 (a, b);
 EXPLAIN
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	break_it	break_it	10	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	break_it	10	NULL	251	Using index for group-by
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a;
 a	MIN(b)	MAX(b)
 1	1	3
@@ -2650,7 +2675,7 @@ a	MIN(b)	MAX(b)
 EXPLAIN
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	break_it	break_it	10	NULL	501	Using index for group-by; Using temporary; Using filesort
+1	SIMPLE	t1	range	NULL	break_it	10	NULL	251	Using index for group-by; Using temporary; Using filesort
 SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
 a	MIN(b)	MAX(b)
 4	1	3
@@ -2660,7 +2685,7 @@ a	MIN(b)	MAX(b)
 EXPLAIN
 SELECT a, MIN(b), MAX(b), AVG(b) FROM t1 GROUP BY a ORDER BY a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	break_it	break_it	10	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	break_it	10	NULL	1000	Using index
 SELECT a, MIN(b), MAX(b), AVG(b) FROM t1 GROUP BY a ORDER BY a DESC;
 a	MIN(b)	MAX(b)	AVG(b)
 4	1	3	2.0000
@@ -2743,9 +2768,9 @@ a	b
 3	13
 explain extended select sql_buffer_result a, max(b)+1 from t1 where a = 0 group by a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	range	PRIMARY,index	PRIMARY	4	NULL	1	100.00	Using where; Using index for group-by; Using temporary
+1	SIMPLE	t1	ref	PRIMARY,index	PRIMARY	4	const	15	100.00	Using index; Using temporary
 Warnings:
-Note	1003	/* select#1 */ select sql_buffer_result `test`.`t1`.`a` AS `a`,(max(`test`.`t1`.`b`) + 1) AS `max(b)+1` from `test`.`t1` where (`test`.`t1`.`a` = 0) group by `test`.`t1`.`a`
+Note	1003	select sql_buffer_result `test`.`t1`.`a` AS `a`,max(`test`.`t1`.`b`) + 1 AS `max(b)+1` from `test`.`t1` where `test`.`t1`.`a` = 0 group by `test`.`t1`.`a`
 drop table t1;
 CREATE TABLE t1 (a int, b int, c int, d int,
 KEY foo (c,d,a,b), KEY bar (c,a,b,d)) engine=RocksDB;
@@ -2758,7 +2783,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT DISTINCT c FROM t1 WHERE d=4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	foo,bar	foo	10	NULL	126	Using where; Using index for group-by
+1	SIMPLE	t1	range	NULL	foo	10	NULL	63	Using where; Using index for group-by
 SELECT DISTINCT c FROM t1 WHERE d=4;
 c
 1
@@ -2780,7 +2805,7 @@ test.t	analyze	status	OK
 EXPLAIN
 SELECT a, MIN(b) FROM t WHERE b <> 0 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	range	a	a	10	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t	range	NULL	a	10	NULL	251	Using where; Using index for group-by
 #should return 1 row
 SELECT a, MIN(b) FROM t WHERE b <> 0 GROUP BY a;
 a	MIN(b)
@@ -2790,7 +2815,7 @@ a	MIN(b)
 EXPLAIN
 SELECT a, MAX(b) FROM t WHERE b <> 1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	range	a	a	10	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t	range	NULL	a	10	NULL	251	Using where; Using index for group-by
 #should return 1 row
 SELECT a, MAX(b) FROM t WHERE b <> 1 GROUP BY a;
 a	MAX(b)
@@ -2801,7 +2826,7 @@ INSERT INTO t SELECT a, 2 FROM t;
 EXPLAIN
 SELECT a, MAX(b) FROM t WHERE b > 0 AND b < 2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	range	a	a	10	NULL	501	Using where; Using index for group-by
+1	SIMPLE	t	range	NULL	a	10	NULL	251	Using where; Using index for group-by
 #should return 1 row
 SELECT a, MAX(b) FROM t WHERE b > 0 AND b < 2 GROUP BY a;
 a	MAX(b)
@@ -2915,7 +2940,7 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using where; Using index
 x	x	x	x	x	x	x	x	x	Using where; Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
@@ -2990,7 +3015,7 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using where; Using index
 x	x	x	x	x	x	x	x	x	Using where; Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
@@ -3072,7 +3097,7 @@ NULL
 EXPLAIN
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-x	x	x	x	x	x	x	x	x	Impossible WHERE noticed after reading const tables
+x	x	x	x	x	x	x	x	x	Using where; Using index
 x	x	x	x	x	x	x	x	x	Using where; Using index
 SELECT MIN( a ) FROM t1 WHERE a = (SELECT a FROM t1 WHERE a < 0);
 MIN( a )
@@ -3119,45 +3144,45 @@ Table	Op	Msg_type	Msg_text
 test.t2	analyze	status	OK
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a) FROM t1;
 COUNT(DISTINCT a)
 2
 EXPLAIN SELECT COUNT(DISTINCT a,b) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT a,b) FROM t1;
 COUNT(DISTINCT a,b)
 16
 EXPLAIN SELECT COUNT(DISTINCT b,a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT b,a) FROM t1;
 COUNT(DISTINCT b,a)
 16
 EXPLAIN SELECT COUNT(DISTINCT b) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	10	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	a	10	NULL	1000	Using index
 SELECT COUNT(DISTINCT b) FROM t1;
 COUNT(DISTINCT b)
 8
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a) FROM t1 GROUP BY a;
 COUNT(DISTINCT a)
 1
 1
 EXPLAIN SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
 COUNT(DISTINCT b)
 8
 8
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 GROUP BY b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	10	NULL	1000	Using index; Using filesort
+1	SIMPLE	t1	index	NULL	a	10	NULL	1000	Using index; Using filesort
 SELECT COUNT(DISTINCT a) FROM t1 GROUP BY b;
 COUNT(DISTINCT a)
 2
@@ -3170,7 +3195,7 @@ COUNT(DISTINCT a)
 2
 EXPLAIN SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	10	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	a	10	NULL	1000	Using index
 SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
 COUNT(DISTINCT a)
 2
@@ -3188,76 +3213,76 @@ COUNT(DISTINCT a)
 2
 EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT c) < 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT c) < 10;
 COUNT(DISTINCT a)
 2
 EXPLAIN SELECT 1 FROM t1 HAVING COUNT(DISTINCT a) < 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT 1 FROM t1 HAVING COUNT(DISTINCT a) < 10;
 1
 1
 EXPLAIN SELECT 1 FROM t1 GROUP BY a HAVING COUNT(DISTINCT b) > 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	10	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t1	range	NULL	a	10	NULL	501	Using index for group-by
 SELECT 1 FROM t1 GROUP BY a HAVING COUNT(DISTINCT b) > 1;
 1
 1
 1
 EXPLAIN SELECT COUNT(DISTINCT t1_1.a) FROM t1 t1_1, t1 t1_2 GROUP BY t1_1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1_1	index	a	a	10	NULL	1000	Using index; Using temporary; Using filesort
-1	SIMPLE	t1_2	index	NULL	a	10	NULL	1000	Using index; Using join buffer (Block Nested Loop)
+1	SIMPLE	t1_1	index	NULL	a	10	NULL	1000	Using index; Using temporary; Using filesort
+1	SIMPLE	t1_2	index	NULL	a	10	NULL	1000	Using index; Using join buffer (flat, BNL join)
 SELECT COUNT(DISTINCT t1_1.a) FROM t1 t1_1, t1 t1_2 GROUP BY t1_1.a;
 COUNT(DISTINCT t1_1.a)
 1
 1
 EXPLAIN SELECT COUNT(DISTINCT a), 12 FROM t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	5	NULL	501	Using index for group-by
+1	SIMPLE	t1	range	NULL	a	5	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a), 12 FROM t1;
 COUNT(DISTINCT a)	12
 2	12
 EXPLAIN SELECT COUNT(DISTINCT a, b, c) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	15	NULL	501	Using index for group-by
 SELECT COUNT(DISTINCT a, b, c) FROM t2;
 COUNT(DISTINCT a, b, c)
 16
 EXPLAIN SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT a) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	5	NULL	251	Using index for group-by
+1	SIMPLE	t2	range	NULL	a	5	NULL	126	Using index for group-by
 SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT a) FROM t2;
 COUNT(DISTINCT a)	SUM(DISTINCT a)	AVG(DISTINCT a)
 2	3	1.5000
 EXPLAIN SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT f) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT f) FROM t2;
 COUNT(DISTINCT a)	SUM(DISTINCT a)	AVG(DISTINCT f)
 2	3	1.0000
 EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, a) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	10	NULL	501	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	10	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, a) FROM t2;
 COUNT(DISTINCT a, b)	COUNT(DISTINCT b, a)
 16	16
 EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, f) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, f) FROM t2;
 COUNT(DISTINCT a, b)	COUNT(DISTINCT b, f)
 16	8
 EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, d) FROM t2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	NULL
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	
 SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, d) FROM t2;
 COUNT(DISTINCT a, b)	COUNT(DISTINCT b, d)
 16	8
 EXPLAIN SELECT a, c, COUNT(DISTINCT c, a, b) FROM t2 GROUP BY a, b, c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	15	NULL	501	Using index for group-by
 SELECT a, c, COUNT(DISTINCT c, a, b) FROM t2 GROUP BY a, b, c;
 a	c	COUNT(DISTINCT c, a, b)
 1	1	1
@@ -3279,7 +3304,7 @@ a	c	COUNT(DISTINCT c, a, b)
 EXPLAIN SELECT COUNT(DISTINCT c, a, b) FROM t2
 WHERE a > 5 AND b BETWEEN 10 AND 20 GROUP BY a, b, c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using where; Using index for group-by (scanning)
+1	SIMPLE	t2	range	a	a	15	NULL	501	Using where; Using index for group-by
 SELECT COUNT(DISTINCT c, a, b) FROM t2
 WHERE a > 5 AND b BETWEEN 10 AND 20 GROUP BY a, b, c;
 COUNT(DISTINCT c, a, b)
@@ -3292,28 +3317,28 @@ GROUP BY b;
 COUNT(DISTINCT b)	SUM(DISTINCT b)
 EXPLAIN SELECT a, COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	10	NULL	501	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	10	NULL	251	Using index for group-by
 SELECT a, COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 a	COUNT(DISTINCT b)	SUM(DISTINCT b)
 1	8	36
 2	8	36
 EXPLAIN SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	10	NULL	501	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	10	NULL	251	Using index for group-by
 SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
 COUNT(DISTINCT b)	SUM(DISTINCT b)
 8	36
 8	36
 EXPLAIN SELECT COUNT(DISTINCT a, b) FROM t2 WHERE c = 13 AND d = 42;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	1000	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1000	Using where
 SELECT COUNT(DISTINCT a, b) FROM t2 WHERE c = 13 AND d = 42;
 COUNT(DISTINCT a, b)
 0
 EXPLAIN SELECT a, COUNT(DISTINCT a), SUM(DISTINCT a) FROM t2
 WHERE b = 13 AND c = 42 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t2	range	NULL	a	15	NULL	126	Using where; Using index for group-by
 SELECT a, COUNT(DISTINCT a), SUM(DISTINCT a) FROM t2
 WHERE b = 13 AND c = 42 GROUP BY a;
 a	COUNT(DISTINCT a)	SUM(DISTINCT a)
@@ -3327,14 +3352,14 @@ COUNT(DISTINCT a, b)	SUM(DISTINCT a)
 0	NULL
 EXPLAIN SELECT SUM(DISTINCT a), MAX(b) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	a	a	15	NULL	1000	Using index
+1	SIMPLE	t2	index	NULL	a	15	NULL	1000	Using index
 SELECT SUM(DISTINCT a), MAX(b) FROM t2 GROUP BY a;
 SUM(DISTINCT a)	MAX(b)
 1	8
 2	8
 EXPLAIN SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	range	a	a	15	NULL	1001	Using index for group-by (scanning)
+1	SIMPLE	t2	range	NULL	a	15	NULL	501	Using index for group-by
 SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
 42 * (a + c + COUNT(DISTINCT c, a, b))
 126
@@ -3355,7 +3380,7 @@ SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
 168
 EXPLAIN SELECT (SUM(DISTINCT a) + MAX(b)) FROM t2 GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t2	index	a	a	15	NULL	1000	Using index
+1	SIMPLE	t2	index	NULL	a	15	NULL	1000	Using index
 SELECT (SUM(DISTINCT a) + MAX(b)) FROM t2 GROUP BY a;
 (SUM(DISTINCT a) + MAX(b))
 9
@@ -3383,7 +3408,7 @@ f1	COUNT(DISTINCT f2)
 3	4
 explain SELECT f1, COUNT(DISTINCT f2) FROM t1 GROUP BY f1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	PRIMARY	PRIMARY	5	NULL	1000	Using index
+1	SIMPLE	t1	index	NULL	PRIMARY	5	NULL	1000	Using index
 drop table t1;
 # End of test#50539.
 #
@@ -3395,9 +3420,6 @@ INSERT INTO t VALUES (1,1), (2,2), (3,3), (4,4), (1,0), (3,2), (4,5);
 ANALYZE TABLE t;
 Table	Op	Msg_type	Msg_text
 test.t	analyze	status	OK
-set optimizer_trace_max_mem_size=1048576;
-set @@session.optimizer_trace='enabled=on';
-set end_markers_in_json=on;
 ANALYZE TABLE t;
 Table	Op	Msg_type	Msg_text
 test.t	analyze	status	OK
@@ -3409,11 +3431,7 @@ a	SUM(DISTINCT a)	MIN(b)
 4	4	4
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b) FROM t GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
 a	SUM(DISTINCT a)	MAX(b)
 1	1	1
@@ -3422,11 +3440,7 @@ a	SUM(DISTINCT a)	MAX(b)
 4	4	5
 EXPLAIN SELECT a, SUM(DISTINCT a), MAX(b) FROM t GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
 a	MAX(b)
 1	1
@@ -3435,21 +3449,13 @@ a	MAX(b)
 4	5
 EXPLAIN SELECT a, MAX(b) FROM t GROUP BY a HAVING SUM(DISTINCT a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
 SUM(DISTINCT a)	MIN(b)	MAX(b)
 10	0	5
 EXPLAIN SELECT SUM(DISTINCT a), MIN(b), MAX(b) FROM t;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
 a	SUM(DISTINCT a)	MIN(b)	MAX(b)
 1	1	0	1
@@ -3458,14 +3464,7 @@ a	SUM(DISTINCT a)	MIN(b)	MAX(b)
 4	4	4	5
 EXPLAIN SELECT a, SUM(DISTINCT a), MIN(b), MAX(b) FROM t GROUP BY a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t	index	a	a	10	NULL	1000	Using index
-SELECT TRACE RLIKE 'have_both_agg_distinct_and_min_max' AS OK
-FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE;
-OK
-1
-SET optimizer_trace_max_mem_size=DEFAULT;
-SET optimizer_trace=DEFAULT;
-SET end_markers_in_json=DEFAULT;
+1	SIMPLE	t	index	NULL	a	10	NULL	1000	Using index
 DROP TABLE t;
 #
 # Bug#18109609: LOOSE INDEX SCAN IS NOT USED WHEN IT SHOULD
@@ -3484,7 +3483,7 @@ Table	Op	Msg_type	Msg_text
 test.t1	analyze	status	OK
 EXPLAIN SELECT MAX(c2), c1 FROM t1 WHERE c1 = 4 GROUP BY c1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	c1	c1	5	NULL	251	Using where; Using index for group-by
+1	SIMPLE	t1	ref	c1	c1	5	const	1000	Using index
 FLUSH STATUS;
 SELECT MAX(c2), c1 FROM t1 WHERE c1 = 4 GROUP BY c1;
 MAX(c2)	c1
@@ -3492,12 +3491,14 @@ MAX(c2)	c1
 SHOW SESSION STATUS LIKE 'Handler_read%';
 Variable_name	Value
 Handler_read_first	0
-Handler_read_key	3
-Handler_read_last	1
-Handler_read_next	0
+Handler_read_key	1
+Handler_read_last	0
+Handler_read_next	20
 Handler_read_prev	0
+Handler_read_retry	0
 Handler_read_rnd	0
+Handler_read_rnd_deleted	0
 Handler_read_rnd_next	0
 DROP TABLE t1;
 # End of test for Bug#18109609
-set global debug="-d,force_group_by";
+set global debug_dbug=@debug_tmp;

storage/rocksdb/mysql-test/rocksdb/t/group_min_max.test

 --source include/have_debug.inc
-set global debug="+d,force_group_by";
+set @debug_tmp= @@debug_dbug;
+set global debug_dbug="+d,force_group_by";
 
 let $engine=RocksDB;
 --source include/group_min_max.inc
 
-set global debug="-d,force_group_by";
+set global debug_dbug=@debug_tmp;