Back-ported the patch of the mysql-5.6 code line that

fixed several defects in the greedy optimization:

1) The greedy optimizer calculated the 'compare-cost' (CPU-cost)
   for iterating over the partial plan result at each level in
   the query plan as 'record_count / (double) TIME_FOR_COMPARE'

   This cost was only used locally for 'best' calculation at each
   level, and *not* accumulated into the total cost for the query plan.

   This fix added the 'CPU-cost' of processing 'current_record_count'
   records at each level to 'current_read_time' *before* it is used as
   'accumulated cost' argument to recursive 
   best_extension_by_limited_search() calls. This ensured that the
   cost of a huge join-fanout early in the QEP was correctly
   reflected in the cost of the final QEP.

   To get identical cost for a 'best' optimized query and a
   straight_join with the same join order, the same change was also
   applied to optimize_straight_join() and get_partial_join_cost()

2) Furthermore to get equal cost for 'best' optimized query and a
   straight_join the new code substrcated the same '0.001' in
   optimize_straight_join() as it had been already done in
   best_extension_by_limited_search()

3) When best_extension_by_limited_search() aggregated the 'best' plan a
   plan was 'best' by the check :

   'if ((search_depth == 1) || (current_read_time < join->best_read))'

   The term '(search_depth == 1' incorrectly caused a new best plan to be
   collected whenever the specified 'search_depth' was reached - even if
   this partial query plan was more expensive than what we had already
   found.

5 files changed, 90 insertions, 81 deletions

diff --git a/mysql-test/suite/pbxt/r/greedy_optimizer.result b/mysql-test/suite/pbxt/r/greedy_optimizer.result
index 7b46f4275b0..6297b51328a 100644
--- a/mysql-test/suite/pbxt/r/greedy_optimizer.result
+++ b/mysql-test/suite/pbxt/r/greedy_optimizer.result
@@ -202,28 +202,28 @@ select @@optimizer_search_depth;
 0
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1372.225316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1372.225316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -231,11 +231,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -243,11 +243,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -255,11 +255,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -267,11 +267,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 set optimizer_search_depth=1;
 select @@optimizer_search_depth;
 @@optimizer_search_depth
@@ -287,7 +287,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
@@ -299,7 +299,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -311,7 +311,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -323,7 +323,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -335,7 +335,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -347,35 +347,35 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 set optimizer_search_depth=62;
 select @@optimizer_search_depth;
 @@optimizer_search_depth
 62
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1372.225316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t2.c22	1	
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t4.c42	1	
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1372.225316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -383,11 +383,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -395,11 +395,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -407,11 +407,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
@@ -419,11 +419,11 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.c21	1	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	290.146368
+Last_query_cost	363.346368
 set optimizer_prune_level=1;
 select @@optimizer_prune_level;
 @@optimizer_prune_level
@@ -443,7 +443,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
@@ -455,55 +455,55 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	
+1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
+1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	
+1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
+1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 set optimizer_search_depth=1;
 select @@optimizer_search_depth;
 @@optimizer_search_depth
@@ -519,7 +519,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
@@ -531,7 +531,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -543,7 +543,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -555,7 +555,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -567,7 +567,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
@@ -579,7 +579,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 set optimizer_search_depth=62;
 select @@optimizer_search_depth;
 @@optimizer_search_depth
@@ -595,7 +595,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c12 = t2.c21 and t2.c22 = t3.c31 and t3.c32 = t4.c41 and t4.c42 = t5.c51 and t5.c52 = t6.c61 and t6.c62 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
@@ -607,54 +607,54 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.c62	1	Using index
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	822.625316
+Last_query_cost	1694.425316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using index
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using index
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using index
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t1, t2, t3, t4, t5, t6, t7 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	
+1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
+1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 explain select t1.c11 from t7, t6, t5, t4, t3, t2, t1 where t1.c11 = t2.c21 and t1.c12 = t3.c31 and t1.c13 = t4.c41 and t1.c14 = t5.c51 and t1.c15 = t6.c61 and t1.c16 = t7.c71 and t2.c22 = t3.c32 and t2.c23 = t4.c42 and t2.c24 = t5.c52 and t2.c25 = t6.c62 and t2.c26 = t7.c72 and t3.c33 = t4.c43 and t3.c34 = t5.c53 and t3.c35 = t6.c63 and t3.c36 = t7.c73 and t4.c42 = t5.c54 and t4.c43 = t6.c64 and t4.c44 = t7.c74 and t5.c52 = t6.c65 and t5.c53 = t7.c75 and t6.c62 = t7.c76;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	
+1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
+1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.c12	1	Using where
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t5	eq_ref	PRIMARY	PRIMARY	4	test.t1.c14	1	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	18	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t7	eq_ref	PRIMARY	PRIMARY	4	test.t1.c16	1	Using where
 show status like 'Last_query_cost';
 Variable_name	Value
-Last_query_cost	795.625316
+Last_query_cost	844.825316
 drop table t1,t2,t3,t4,t5,t6,t7;
 set join_cache_level=@save_join_cache_level;
diff --git a/mysql-test/suite/pbxt/r/join.result b/mysql-test/suite/pbxt/r/join.result
index 5035f5da9bd..3a1759a18f4 100644
--- a/mysql-test/suite/pbxt/r/join.result
+++ b/mysql-test/suite/pbxt/r/join.result
@@ -801,7 +801,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	B	eq_ref	PRIMARY	PRIMARY	4	test.A.b	1	
 show status like '%cost%';
 Variable_name	Value
-Last_query_cost	24.262158
+Last_query_cost	28.262158
 select '^^: The above should be ~= 20 + cost(select * from t1). Value less than 20 is an error' Z;
 Z
 ^^: The above should be ~= 20 + cost(select * from t1). Value less than 20 is an error
diff --git a/mysql-test/suite/pbxt/r/select.result b/mysql-test/suite/pbxt/r/select.result
index 869df25504a..58a1a326f6b 100644
--- a/mysql-test/suite/pbxt/r/select.result
+++ b/mysql-test/suite/pbxt/r/select.result
@@ -2204,10 +2204,10 @@ a	a
 select * from (t1 as t2 left join t1 as t3 using (a)) inner join t1 on t1.a>1;
 a	a
 1	2
-2	2
-3	2
 1	3
+2	2
 2	3
+3	2
 3	3
 select * from t1 inner join (t1 as t2 left join t1 as t3 using (a)) on t1.a>1;
 a	a
diff --git a/mysql-test/suite/pbxt/r/subselect.result b/mysql-test/suite/pbxt/r/subselect.result
index cc513a1444d..0a065e61edf 100644
--- a/mysql-test/suite/pbxt/r/subselect.result
+++ b/mysql-test/suite/pbxt/r/subselect.result
@@ -1366,8 +1366,8 @@ a
 explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	a	a	5	NULL	4	100.00	Using where; Using index
-1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using index; Start temporary
-1	PRIMARY	t3	index	a	a	5	NULL	3	100.00	Using where; Using index; End temporary
+1	PRIMARY	t1	ref	a	a	5	test.t2.a	1	100.00	Using where; Using index
+1	PRIMARY	t3	ref	a	a	5	test.t1.b	1	100.00	Using index; FirstMatch(t2)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1` join `test`.`t3`) where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))
 insert into t1 values (3,31);
@@ -4225,6 +4225,9 @@ LEFT(t1.a1,1)
 SELECT a2 FROM t2 WHERE t2.a2 IN (SELECT t1.a1 FROM t1,t3 WHERE t1.b1=t3.a3);
 a2
 DROP TABLE t1, t2, t3;
+SET @save_optimizer_switch=@@optimizer_switch;
+SET optimizer_switch='semijoin_with_cache=off';
+SET optimizer_switch='materialization=off';
 CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
 INSERT INTO t1 VALUES ('a', 'aa');
 INSERT INTO t1 VALUES ('a', 'aaa');
@@ -4256,6 +4259,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
 a	b
 DROP TABLE t1,t2;
+SET optimizer_switch= @save_optimizer_switch;
 CREATE TABLE t1(a INT, b INT);
 INSERT INTO t1 VALUES (1,1), (1,2), (2,3), (2,4);
 EXPLAIN 
diff --git a/mysql-test/suite/pbxt/t/subselect.test b/mysql-test/suite/pbxt/t/subselect.test
index 5f0835e0b03..aae7ff2d5f5 100644
--- a/mysql-test/suite/pbxt/t/subselect.test
+++ b/mysql-test/suite/pbxt/t/subselect.test
@@ -3099,6 +3099,10 @@ DROP TABLE t1, t2, t3;
 # Bug #30788: Inconsistent retrieval of char/varchar
 #
 
+SET @save_optimizer_switch=@@optimizer_switch;
+SET optimizer_switch='semijoin_with_cache=off';
+SET optimizer_switch='materialization=off';
+
 CREATE TABLE t1 (a CHAR(1), b VARCHAR(10));
 INSERT INTO t1 VALUES ('a', 'aa');
 INSERT INTO t1 VALUES ('a', 'aaa');
@@ -3120,6 +3124,7 @@ SELECT a,b FROM t1 WHERE b IN (SELECT a FROM t1 WHERE LENGTH(a)<500);
 
 DROP TABLE t1,t2;
 
+SET optimizer_switch= @save_optimizer_switch;
 
 #
 # Bug #32400: Complex SELECT query returns correct result only on some