MDEV-6657: Poor plan choice for ORDER BY key DESC optimization...bb-10.1-mdev6657

The problem was caused by the following scenario:
- range optimizer picks an index IDX1 which doesn't match the ORDER BY ...
  LIMIT clause.
- test_if_skip_sort_order() decides to switch to index IDX2 which matches
  the ORDER BY ... LIMIT.
- it runs SQL_SELECT::test_quick_select() for the second time to produce
  an quick select for IDX2.
- However, test_quick_select() would figure that full index scan on IDX1
  is still cheaper (its calculations ignore the LIMIT n).

Fixed this by
- passing force_quick_range=true to test_quick_select()
- in test_quick_select, don't consider full index scans if the mentioned
  parameter is true.

Numerous changes in .result files are caused by test_quick_select() being
run after "early/late NULLs filtering" feature has injected NOT NULL
condition.

15 files changed, 129 insertions, 23 deletions

diff --git a/mysql-test/r/myisam_explain_non_select_all.result b/mysql-test/r/myisam_explain_non_select_all.result
index 285a1ca6786..a9eeee8548c 100644
--- a/mysql-test/r/myisam_explain_non_select_all.result
+++ b/mysql-test/r/myisam_explain_non_select_all.result
@@ -674,14 +674,14 @@ FLUSH STATUS;
 FLUSH TABLES;
 EXPLAIN EXTENDED SELECT * FROM t1 WHERE t1.a > 0 ORDER BY t1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	3	100.00	Using where; Using index
+1	SIMPLE	t1	range	PRIMARY	PRIMARY	4	NULL	3	100.00	Using where; Using index
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a` from `test`.`t1` where (`test`.`t1`.`a` > 0) order by `test`.`t1`.`a`
 # Status of EXPLAIN EXTENDED "equivalent" SELECT query execution
 Variable_name	Value
 # Status of "equivalent" SELECT query execution:
 Variable_name	Value
-Handler_read_first	1
+Handler_read_key	1
 Handler_read_next	3
 # Status of testing query execution:
 Variable_name	Value
diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result
index 294142737d9..aba8d6c201c 100644
--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -297,7 +297,7 @@ create table t1 (a int not null, b int, c varchar(10), key (a, b, c));
 insert into t1 values (1, NULL, NULL), (1, NULL, 'b'), (1, 1, NULL), (1, 1, 'b'), (1, 1, 'b'), (2, 1, 'a'), (2, 1, 'b'), (2, 2, 'a'), (2, 2, 'b'), (2, 3, 'c'),(1,3,'b');
 explain select * from t1 where (a = 1 and b is null and c = 'b') or (a > 2) order by a desc;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	22	NULL	11	Using where; Using index
+1	SIMPLE	t1	range	a	a	22	NULL	2	Using where; Using index
 select * from t1 where (a = 1 and b is null and c = 'b') or (a > 2) order by a desc;
 a	b	c
 1	NULL	b
@@ -2569,7 +2569,7 @@ SELECT * FROM t1 r JOIN t1 s ON r.a = s.a
 WHERE s.a IN (2,9) OR s.a < 100  AND s.a != 0
 ORDER BY 1 LIMIT 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	r	index	PRIMARY	PRIMARY	4	NULL	10	100.00	Using where; Using index
+1	SIMPLE	r	range	PRIMARY	PRIMARY	4	NULL	12	100.00	Using where; Using index
 1	SIMPLE	s	eq_ref	PRIMARY	PRIMARY	4	test.r.a	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`r`.`a` AS `a`,`test`.`s`.`a` AS `a` from `test`.`t1` `r` join `test`.`t1` `s` where ((`test`.`s`.`a` = `test`.`r`.`a`) and ((`test`.`r`.`a` in (2,9)) or ((`test`.`r`.`a` < 100) and (`test`.`r`.`a` <> 0)))) order by 1 limit 10
@@ -2600,7 +2600,7 @@ CREATE TABLE t1 (a INT,KEY (a));
 INSERT INTO t1 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
 EXPLAIN SELECT DISTINCT a,1 FROM t1 WHERE a <> 1 ORDER BY a DESC;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	index	a	a	5	NULL	10	Using where; Using index; Using filesort
+1	SIMPLE	t1	range	a	a	5	NULL	10	Using where; Using index
 SELECT DISTINCT a,1 FROM t1 WHERE a <> 1 ORDER BY a DESC;
 a	1
 10	1
diff --git a/mysql-test/r/show_explain.result b/mysql-test/r/show_explain.result
index 3695384bac4..8aefb552d57 100644
--- a/mysql-test/r/show_explain.result
+++ b/mysql-test/r/show_explain.result
@@ -1036,7 +1036,7 @@ explain
 SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	system	NULL	NULL	NULL	NULL	1	
-1	SIMPLE	t1	index	b	b	6	NULL	107	Using where; Using index
+1	SIMPLE	t1	range	b	b	6	NULL	107	Using where; Using index
 1	SIMPLE	t3	ref	PRIMARY	PRIMARY	5	test.t1.b	1	Using index
 set @show_explain_probe_select_id=1;
 set debug_dbug='+d,show_explain_probe_do_select';
@@ -1044,7 +1044,7 @@ SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, fie
 show explain for $thr2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	system	NULL	NULL	NULL	NULL	1	Using filesort
-1	SIMPLE	t1	index	b	b	6	NULL	107	Using where; Using index
+1	SIMPLE	t1	range	b	b	6	NULL	107	Using where; Using index
 1	SIMPLE	t3	ref	PRIMARY	PRIMARY	5	test.t1.b	1	Using index
 Warnings:
 Note	1003	SELECT b AS field1, b AS field2 FROM t1, t2, t3 WHERE d = b ORDER BY field1, field2
diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 5678a455234..55184f42c97 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -6974,7 +6974,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
@@ -7008,7 +7008,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
diff --git a/mysql-test/r/subselect_mat.result b/mysql-test/r/subselect_mat.result
index 6cc627ad16c..30b020cbcf6 100644
--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -103,7 +103,7 @@ explain extended
 select * from t1i where a1 in (select max(b1) from t2i where b1 > '0' group by b1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1i	index	NULL	#	18	#	3	100.00	#
-2	MATERIALIZED	t2i	index	it2i1,it2i3	#	9	#	5	100.00	#
+2	MATERIALIZED	t2i	range	it2i1,it2i3	#	9	#	5	100.00	#
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from `test`.`t1i` where <expr_cache><`test`.`t1i`.`a1`>(<in_optimizer>(`test`.`t1i`.`a1`,`test`.`t1i`.`a1` in ( <materialize> (select max(`test`.`t2i`.`b1`) from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1` ), <primary_index_lookup>(`test`.`t1i`.`a1` in <temporary table> on distinct_key where ((`test`.`t1i`.`a1` = `<subquery2>`.`max(b1)`))))))
 select * from t1i where a1 in (select max(b1) from t2i where b1 > '0' group by b1);
diff --git a/mysql-test/r/subselect_no_exists_to_in.result b/mysql-test/r/subselect_no_exists_to_in.result
index 5434bb920e3..58ee06d754d 100644
--- a/mysql-test/r/subselect_no_exists_to_in.result
+++ b/mysql-test/r/subselect_no_exists_to_in.result
@@ -6974,7 +6974,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
@@ -7008,7 +7008,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
diff --git a/mysql-test/r/subselect_no_mat.result b/mysql-test/r/subselect_no_mat.result
index 3325889e1e0..53307efdb89 100644
--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -6968,7 +6968,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
@@ -7001,7 +7001,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
diff --git a/mysql-test/r/subselect_no_opts.result b/mysql-test/r/subselect_no_opts.result
index 01af3ea4b16..c228ae46347 100644
--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -6965,7 +6965,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
@@ -6999,7 +6999,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
diff --git a/mysql-test/r/subselect_no_scache.result b/mysql-test/r/subselect_no_scache.result
index 16ebf7a4199..7d1dde6498e 100644
--- a/mysql-test/r/subselect_no_scache.result
+++ b/mysql-test/r/subselect_no_scache.result
@@ -6980,7 +6980,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
@@ -7014,7 +7014,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
diff --git a/mysql-test/r/subselect_no_semijoin.result b/mysql-test/r/subselect_no_semijoin.result
index d98f7ad67de..c850644fbaa 100644
--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -6965,7 +6965,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
@@ -6999,7 +6999,7 @@ INSERT INTO t2 VALUES (45),(17),(20);
 EXPLAIN SELECT * FROM t1 WHERE EXISTS ( SELECT a FROM t1, t2 WHERE b = a GROUP BY a HAVING a <> 1 ) ;
 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	index	a	a	5	NULL	2	Using where; Using index
+2	SUBQUERY	t1	range	a	a	5	NULL	2	Using where; Using index
 2	SUBQUERY	t2	ref	b	b	5	test.t1.a	2	Using index
 DROP TABLE t1,t2;
 #
diff --git a/mysql-test/r/subselect_sj_mat.result b/mysql-test/r/subselect_sj_mat.result
index 95dfc34777b..7417ab56ff8 100644
--- a/mysql-test/r/subselect_sj_mat.result
+++ b/mysql-test/r/subselect_sj_mat.result
@@ -107,7 +107,7 @@ select * from t1i where a1 in (select max(b1) from t2i where b1 > '0' group by b
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1i	index	it1i1,it1i3	#	18	#	3	100.00	#
 1	PRIMARY	<subquery2>	eq_ref	distinct_key	#	8	#	1	100.00	#
-2	MATERIALIZED	t2i	index	it2i1,it2i3	#	9	#	5	100.00	#
+2	MATERIALIZED	t2i	range	it2i1,it2i3	#	9	#	5	100.00	#
 Warnings:
 Note	1003	select `test`.`t1i`.`a1` AS `a1`,`test`.`t1i`.`a2` AS `a2` from  <materialize> (select max(`test`.`t2i`.`b1`) from `test`.`t2i` where (`test`.`t2i`.`b1` > '0') group by `test`.`t2i`.`b1`) join `test`.`t1i` where (`<subquery2>`.`max(b1)` = `test`.`t1i`.`a1`)
 select * from t1i where a1 in (select max(b1) from t2i where b1 > '0' group by b1);
diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 2616e044025..7a584eed742 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -3056,7 +3056,7 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     param.alloced_sel_args= 0;
 
     /* Calculate cost of full index read for the shortest covering index */
-    if (!head->covering_keys.is_clear_all())
+    if (!force_quick_range && !head->covering_keys.is_clear_all())
     {
       int key_for_use= find_shortest_key(head, &head->covering_keys);
       double key_read_time= head->file->keyread_time(key_for_use, 1, records) +
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 05c88a5f534..860f0cd346c 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -20168,7 +20168,7 @@ test_if_skip_sort_order(JOIN_TAB *tab,ORDER *order,ha_rows select_limit,
                                          (tab->join->select_options &
                                           OPTION_FOUND_ROWS) ?
                                          HA_POS_ERROR :
-                                         tab->join->unit->select_limit_cnt,0,
+                                         tab->join->unit->select_limit_cnt,TRUE,
                                          TRUE) <= 0;
           if (res)
           {
@@ -20286,6 +20286,12 @@ check_reverse_order:
       */
       if (!table->covering_keys.is_set(best_key))
         table->disable_keyread();
+      else
+      {
+        if (!table->key_read)
+          table->enable_keyread();
+      }
+
       if (!quick_created)
       {
         if (select)                  // Throw any existing quick select
diff --git a/storage/tokudb/mysql-test/tokudb_mariadb/r/mdev6657.result b/storage/tokudb/mysql-test/tokudb_mariadb/r/mdev6657.result
new file mode 100644
index 00000000000..a09e2f2010e
--- /dev/null
+++ b/storage/tokudb/mysql-test/tokudb_mariadb/r/mdev6657.result
@@ -0,0 +1,47 @@
+drop table if exists t1,t2,t3;
+create table t1(a int);
+insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t2(a int);
+insert into t2 select A.a + B.a* 10 + C.a * 100 from t1 A, t1 B, t1 C;
+CREATE TABLE t3 (
+col1 int(10) unsigned NOT NULL DEFAULT '0',
+col2 mediumint(8) unsigned NOT NULL DEFAULT '0',
+col3 smallint(5) NOT NULL DEFAULT '1',
+filler varchar(255) DEFAULT NULL,
+PRIMARY KEY (col1,col2,col3),
+KEY key1 (col1,col2) USING BTREE
+) ENGINE=TokuDB DEFAULT CHARSET=latin1 PACK_KEYS=1 COMPRESSION=TOKUDB_LZMA;
+insert into t3 select 1300000000+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1400000000+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1410799999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1410899999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1410999999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411099999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411199999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411299999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411399999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411499999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411599999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411699999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411899999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411999999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1412099999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1412199999+a, 12345, 7890, 'data' from t2;
+# The following must use range(PRIMARY):
+explain 
+select col1,col2,col3  
+from t3
+where col1 <= 1410799999 
+order by col1 desc,col2 desc,col3 desc limit 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t3	range	PRIMARY,key1	PRIMARY	4	NULL	2001	Using where; Using index
+# The same query but the constant is bigger. 
+# The query should use range(PRIMARY), not full index scan:
+explain 
+select col1,col2,col3  
+from t3
+where col1 <= 1412199999 
+order by col1 desc, col2 desc, col3 desc limit 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t3	range	PRIMARY,key1	PRIMARY	4	NULL	15001	Using where; Using index
+drop table t1,t2,t3;
diff --git a/storage/tokudb/mysql-test/tokudb_mariadb/t/mdev6657.test b/storage/tokudb/mysql-test/tokudb_mariadb/t/mdev6657.test
new file mode 100644
index 00000000000..636dee1cde8
--- /dev/null
+++ b/storage/tokudb/mysql-test/tokudb_mariadb/t/mdev6657.test
@@ -0,0 +1,53 @@
+--disable_warnings
+drop table if exists t1,t2,t3;
+--enable_warnings
+
+create table t1(a int);
+insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t2(a int);
+insert into t2 select A.a + B.a* 10 + C.a * 100 from t1 A, t1 B, t1 C;
+
+CREATE TABLE t3 (
+  col1 int(10) unsigned NOT NULL DEFAULT '0',
+  col2 mediumint(8) unsigned NOT NULL DEFAULT '0',
+  col3 smallint(5) NOT NULL DEFAULT '1',
+  filler varchar(255) DEFAULT NULL,
+  PRIMARY KEY (col1,col2,col3),
+  KEY key1 (col1,col2) USING BTREE
+) ENGINE=TokuDB DEFAULT CHARSET=latin1 PACK_KEYS=1 COMPRESSION=TOKUDB_LZMA;
+
+insert into t3 select 1300000000+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1400000000+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1410799999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1410899999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1410999999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411099999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411199999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411299999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411399999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411499999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411599999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411699999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411899999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1411999999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1412099999+a, 12345, 7890, 'data' from t2;
+insert into t3 select 1412199999+a, 12345, 7890, 'data' from t2;
+
+--echo # The following must use range(PRIMARY):
+explain 
+select col1,col2,col3  
+from t3
+where col1 <= 1410799999 
+order by col1 desc,col2 desc,col3 desc limit 1;
+
+--echo # The same query but the constant is bigger. 
+--echo # The query should use range(PRIMARY), not full index scan:
+explain 
+select col1,col2,col3  
+from t3
+where col1 <= 1412199999 
+order by col1 desc, col2 desc, col3 desc limit 1;
+
+drop table t1,t2,t3;
+