BUG#16393: Let the 'ref' optimizer use ON condition of nested join to construct

'ref' accesses to all tables that are direct children of the nested join and are 
not inner wrt their siblings.

1 files changed, 17 insertions, 3 deletions

diff --git a/mysql-test/r/join_nested.result b/mysql-test/r/join_nested.result
index 6b7293d46bc..faad969fcd1 100644
--- a/mysql-test/r/join_nested.result
+++ b/mysql-test/r/join_nested.result
@@ -960,7 +960,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	2	Using where
-1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	Using where
@@ -1009,7 +1009,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	2	Using where
-1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t8	ref	idx_b	idx_b	5	test.t5.b	2	Using where
@@ -1059,7 +1059,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	2	Using where
-1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t5	ALL	idx_b	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	Using where
 1	SIMPLE	t8	ref	idx_b	idx_b	5	test.t5.b	2	Using where
@@ -1467,3 +1467,17 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ref	a	a	5	test.t4.b	X	
 1	SIMPLE	t5	ref	a	a	5	test.t3.b	X	
 drop table t0, t1, t2, t3, t4, t5, t6, t7;
+create table t1 (a int);
+insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t2 (a int, filler char(100), key(a));
+insert into t2 select A.a + 10*B.a, '' from t1 A, t1 B;
+create table t3 like t2;
+insert into t3 select * from t2;
+explain select * from t1 left join 
+(t2 left join t3 on (t2.a = t3.a)) 
+on (t1.a = t2.a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	10	
+1	SIMPLE	t2	ref	a	a	5	test.t1.a	1	
+1	SIMPLE	t3	ref	a	a	5	test.t2.a	1	
+drop table t1, t2, t3;