MWL#128: Added into EXPLAIN output info about types of the used join buffers and

about the employed join algorithms. Refactored constructors of the JOIN_CACHE* classes.

MWL#128: Added into EXPLAIN output info about types of the used join buffers and
about the employed join algorithms. Refactored constructors of the JOIN_CACHE* classes.
39bd4d1f · Igor Babaev · d64ce287 · 39bd4d1f · 39bd4d1f · 39bd4d1f
Commit 39bd4d1f authored Oct 18, 2010 by Igor Babaev
65 changed files
--- a/mysql-test/r/archive_gis.result
+++ b/mysql-test/r/archive_gis.result
@@ -403,7 +403,7 @@ Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
 FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	g1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-1	SIMPLE	g2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+1	SIMPLE	g2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
 DROP TABLE gis_point, gis_line, gis_polygon, gis_multi_point, gis_multi_line, gis_multi_polygon, gis_geometrycollection, gis_geometry;

--- a/mysql-test/r/compress.result
+++ b/mysql-test/r/compress.result
@@ -1435,7 +1435,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008

--- a/mysql-test/r/ctype_utf8.result
+++ b/mysql-test/r/ctype_utf8.result
@@ -1537,7 +1537,7 @@ explain
 select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	Y	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
-1	SIMPLE	Z	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer
+1	SIMPLE	Z	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
 select substr(Z.a,-1), Z.a from t1 as Y join t1 as Z on Y.a=Z.a order by 1;
 substr(Z.a,-1)	a
 3	123

--- a/mysql-test/r/derived.result
+++ b/mysql-test/r/derived.result
@@ -58,7 +58,7 @@ a	b	a	b
 explain select * from t1 as x1, (select * from t1) as x2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	4	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	4	
 drop table if exists  t2,t3;
 select * from (select 1) as a;
@@ -189,13 +189,13 @@ pla_id	test
 explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	m2	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 2	DERIVED	mp	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
 2	DERIVED	m1	eq_ref	PRIMARY	PRIMARY	3	test.mp.mat_id	1	
 explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2  INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	m2	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 2	DERIVED	mp	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
 2	DERIVED	m1	eq_ref	PRIMARY	PRIMARY	3	test.mp.mat_id	1	
 drop table t1,t2;
@@ -246,7 +246,7 @@ a	a
 explain select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<derived4>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer
+1	PRIMARY	<derived4>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 4	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
 5	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	
 NULL	UNION RESULT	<union4,5>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -313,7 +313,7 @@ explain SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	3	Using temporary; Using filesort
 2	DERIVED	x	ALL	NULL	NULL	NULL	NULL	17	Using temporary; Using filesort
-2	DERIVED	y	ALL	NULL	NULL	NULL	NULL	17	Using where; Using join buffer
+2	DERIVED	y	ALL	NULL	NULL	NULL	NULL	17	Using where; Using join buffer (flat, BNL join)
 drop table t1;
 create table t2 (a int, b int, primary key (a));
 insert into t2 values (1,7),(2,7);

--- a/mysql-test/r/distinct.result
+++ b/mysql-test/r/distinct.result
@@ -175,7 +175,7 @@ explain SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	PRIMARY	NULL	NULL	NULL	4	Using where; Using temporary
 1	SIMPLE	t3	ref	a	a	5	test.t1.b	2	Using index
-1	SIMPLE	t2	index	a	a	4	NULL	5	Using where; Using index; Distinct; Using join buffer
+1	SIMPLE	t2	index	a	a	4	NULL	5	Using where; Using index; Distinct; Using join buffer (flat, BNL join)
 SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
 a
 1
@@ -300,11 +300,11 @@ WHERE
 AND ((t1.id=j_lj_t3.id AND t3_lj.id IS NULL) OR (t1.id=t3.id AND t3.idx=2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	id	id	4	NULL	2	Using index; Using temporary
-1	SIMPLE	t2	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer
+1	SIMPLE	t2	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer
+1	SIMPLE	t3	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer (flat, BNL join)
-1	SIMPLE	j_lj_t2	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer
+1	SIMPLE	j_lj_t2	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer (flat, BNL join)
 1	SIMPLE	t2_lj	ref	id	id	4	test.j_lj_t2.id	1	Using where; Using index; Distinct
-1	SIMPLE	j_lj_t3	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer
+1	SIMPLE	j_lj_t3	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer (flat, BNL join)
 1	SIMPLE	t3_lj	ref	id	id	4	test.j_lj_t3.id	1	Using where; Using index; Distinct
 SELECT DISTINCT
 t1.id
@@ -515,7 +515,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1_1	ALL	NULL	NULL	NULL	NULL	3	Using temporary
-1	SIMPLE	t1_2	index	NULL	PRIMARY	4	NULL	3	Using index; Distinct; Using join buffer
+1	SIMPLE	t1_2	index	NULL	PRIMARY	4	NULL	3	Using index; Distinct; Using join buffer (flat, BNL join)
 EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2
 WHERE t1_1.a = t1_2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

--- a/mysql-test/r/explain.result
+++ b/mysql-test/r/explain.result
@@ -116,7 +116,7 @@ FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
 EXPLAIN EXTENDED SELECT 1
@@ -124,7 +124,7 @@ FROM (SELECT COUNT(DISTINCT t1.a) FROM t1,t2 GROUP BY t1.a) AS s1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
 prepare s1 from 
@@ -134,7 +134,7 @@ execute s1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
 prepare s1 from 
@@ -144,14 +144,14 @@ execute s1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
 execute s1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select count(distinct `test`.`t1`.`a`) AS `COUNT(DISTINCT t1.a)` from `test`.`t1` join `test`.`t2` group by `test`.`t1`.`a`) `s1`
 DROP TABLE t1,t2;

--- a/mysql-test/r/func_gconcat.result
+++ b/mysql-test/r/func_gconcat.result
@@ -986,7 +986,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort; Distinct
-2	DERIVED	td	ALL	NULL	NULL	NULL	NULL	2	100.00	Distinct; Using join buffer
+2	DERIVED	td	ALL	NULL	NULL	NULL	NULL	2	100.00	Distinct; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select distinct group_concat(`test`.`td`.`f1` separator ',') AS `GROUP_CONCAT(td.f1)` from `test`.`t1` join `test`.`t1` `td` group by `test`.`td`.`f1`) `d` join `test`.`t1`
 SELECT 1 FROM
@@ -1006,7 +1006,7 @@ t1 t2, t1 GROUP BY t1.a) AS d;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	100.00	
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select 1 AS `1` from (select group_concat(`test`.`t1`.`a` order by `test`.`t1`.`a` ASC separator ',') AS `GROUP_CONCAT(t1.a ORDER BY t1.a ASC)` from `test`.`t1` `t2` join `test`.`t1` group by `test`.`t1`.`a`) `d`
 DROP TABLE t1;

--- a/mysql-test/r/func_group.result
+++ b/mysql-test/r/func_group.result
@@ -614,7 +614,7 @@ explain
 select max(t1.a3), min(t2.a2) from t1, t2 where t1.a2 = 2 and t1.a3 < 'MIN' and t2.a3 > 'CA';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	k1	k1	7	NULL	1	Using where; Using index
-1	SIMPLE	t2	range	k1	k1	3	NULL	4	Using where; Using index; Using join buffer
+1	SIMPLE	t2	range	k1	k1	3	NULL	4	Using where; Using index; Using join buffer (flat, BNL join)
 explain
 select min(a4 - 0.01) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -651,7 +651,7 @@ explain
 select concat(min(t1.a1),min(t2.a4)) from t1, t2 where t2.a4 <> 'AME';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	k2	k2	4	NULL	6	Using where; Using index
-1	SIMPLE	t1	index	NULL	PRIMARY	3	NULL	15	Using index; Using join buffer
+1	SIMPLE	t1	index	NULL	PRIMARY	3	NULL	15	Using index; Using join buffer (flat, BNL join)
 drop table t1, t2;
 create table t1 (a char(10));
 insert into t1 values ('a'),('b'),('c');

--- a/mysql-test/r/func_group_innodb.result
+++ b/mysql-test/r/func_group_innodb.result
@@ -79,7 +79,7 @@ min(7)
 explain select min(7) from t2i join t1i;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2i	ALL	NULL	NULL	NULL	NULL	1	
-1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer
+1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
 select min(7) from t2i join t1i;
 min(7)
 NULL
@@ -95,7 +95,7 @@ max(7)
 explain select max(7) from t2i join t1i;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2i	ALL	NULL	NULL	NULL	NULL	1	
-1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer
+1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
 select max(7) from t2i join t1i;
 max(7)
 NULL

--- a/mysql-test/r/func_str.result
+++ b/mysql-test/r/func_str.result
@@ -2550,12 +2550,12 @@ insert into t1 values (-1),(null);
 explain select 1 as a from t1,(select decode(f1,f1) as b from t1) a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
 explain select 1 as a from t1,(select encode(f1,f1) as b from t1) a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
 drop table t1;
 #

--- a/mysql-test/r/gis.result
+++ b/mysql-test/r/gis.result
@@ -395,7 +395,7 @@ Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
 FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	g1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-1	SIMPLE	g2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+1	SIMPLE	g2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
 DROP TABLE gis_point, gis_line, gis_polygon, gis_multi_point, gis_multi_line, gis_multi_polygon, gis_geometrycollection, gis_geometry;

--- a/mysql-test/r/greedy_optimizer.result
+++ b/mysql-test/r/greedy_optimizer.result
--- a/mysql-test/r/group_by.result
+++ b/mysql-test/r/group_by.result
@@ -537,11 +537,11 @@ a	b
 explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
-1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b ORDER BY NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary
-1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 drop table t1,t2;
 create table t1 (a int, b int);
 insert into t1 values (1, 4),(10, 40),(1, 4),(10, 43),(1, 4),(10, 41),(1, 4),(10, 43),(1, 4);

--- a/mysql-test/r/group_min_max.result
+++ b/mysql-test/r/group_min_max.result
@@ -2267,7 +2267,7 @@ 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_outer1	ref	a	a	5	const	1	Using where; Using index
-1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer
+1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer (flat, BNL join)
 2	SUBQUERY	t1	range	NULL	a	5	NULL	8	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;

--- a/mysql-test/r/index_merge_myisam.result
+++ b/mysql-test/r/index_merge_myisam.result
@@ -271,7 +271,7 @@ explain select * from t0,t1 where t0.key1 = 5 and
 (t1.key1 = t0.key1 or t1.key8 = t0.key1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t0	ref	i1	i1	4	const	1	
-1	SIMPLE	t1	index_merge	i1,i8	i1,i8	4,4	NULL	2	Using union(i1,i8); Using where; Using join buffer
+1	SIMPLE	t1	index_merge	i1,i8	i1,i8	4,4	NULL	2	Using union(i1,i8); Using where; Using join buffer (flat, BNL join)
 explain select * from t0,t1 where t0.key1 < 3 and
 (t1.key1 = t0.key1 or t1.key8 = t0.key1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -348,7 +348,7 @@ where (A.key1 < 500000 or A.key2 < 3)
 and   (B.key1 < 500000 or B.key2 < 3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	A	index_merge	i1,i2	i1,i2	4,4	NULL	1013	Using sort_union(i1,i2); Using where
-1	SIMPLE	B	index_merge	i1,i2	i1,i2	4,4	NULL	1013	Using sort_union(i1,i2); Using where; Using join buffer
+1	SIMPLE	B	index_merge	i1,i2	i1,i2	4,4	NULL	1013	Using sort_union(i1,i2); Using where; Using join buffer (flat, BNL join)
 select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
 from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
 where (A.key1 < 500000 or A.key2 < 3)
@@ -362,7 +362,7 @@ where (A.key1 = 1 or A.key2 = 1)
 and   (B.key1 = 1 or B.key2 = 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	A	index_merge	i1,i2	i1,i2	4,4	NULL	1020	Using union(i1,i2); Using where
-1	SIMPLE	B	index_merge	i1,i2	i1,i2	4,4	NULL	1020	Using union(i1,i2); Using where; Using join buffer
+1	SIMPLE	B	index_merge	i1,i2	i1,i2	4,4	NULL	1020	Using union(i1,i2); Using where; Using join buffer (flat, BNL join)
 select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
 from t0 as A force index(i1,i2), t0 as B force index (i1,i2)
 where (A.key1 = 1 or A.key2 = 1)
@@ -377,7 +377,7 @@ where (A.key1 = 1 and A.key2 = 1 and A.key3 = 1 and A.key4=1 and A.key5=1 and A.
 and (B.key1 = 1 and B.key2 = 1 and B.key3 = 1 and B.key4=1 and B.key5=1 and B.key6=1 and B.key7 = 1 or B.key8=1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	A	index_merge	i1,i2,i3,i4,i5,i6,i7?,i8	i2,i3,i4,i5,i6,i7?,i8	X	NULL	#	Using union(intersect(i2,i3,i4,i5,i6,i7?),i8); Using where
-1	SIMPLE	B	index_merge	i1,i2,i3,i4,i5,i6,i7?,i8	i2,i3,i4,i5,i6,i7?,i8	X	NULL	#	Using union(intersect(i2,i3,i4,i5,i6,i7?),i8); Using where; Using join buffer
+1	SIMPLE	B	index_merge	i1,i2,i3,i4,i5,i6,i7?,i8	i2,i3,i4,i5,i6,i7?,i8	X	NULL	#	Using union(intersect(i2,i3,i4,i5,i6,i7?),i8); Using where; Using join buffer (flat, BNL join)
 select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5)
 from t0 as A, t0 as B
 where (A.key1 = 1 and A.key2 = 1 and A.key3 = 1 and A.key4=1 and A.key5=1 and A.key6=1 and A.key7 = 1 or A.key8=1)

--- a/mysql-test/r/information_schema.result
+++ b/mysql-test/r/information_schema.result
@@ -323,7 +323,7 @@ information_schema.SCHEMATA b where
 a.ROUTINE_SCHEMA = b.SCHEMA_NAME;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	NULL	
-1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Using join buffer
+1	SIMPLE	#	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Using join buffer (flat, BNL join)
 select a.ROUTINE_NAME, b.name from information_schema.ROUTINES a,
 mysql.proc b where a.ROUTINE_NAME = convert(b.name using utf8) AND a.ROUTINE_SCHEMA='test' order by 1;
 ROUTINE_NAME	name
@@ -1450,7 +1450,7 @@ from information_schema.tables a, information_schema.columns b
 where a.table_name='t1' and a.table_schema='test' and b.table_name=a.table_name;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	a	ALL	NULL	TABLE_SCHEMA,TABLE_NAME	NULL	NULL	NULL	Using where; Skip_open_table; Scanned 0 databases
-1	SIMPLE	b	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Open_frm_only; Scanned all databases; Using join buffer
+1	SIMPLE	b	ALL	NULL	NULL	NULL	NULL	NULL	Using where; Open_frm_only; Scanned all databases; Using join buffer (flat, BNL join)
 SELECT * FROM INFORMATION_SCHEMA.SCHEMATA
 WHERE SCHEMA_NAME = 'mysqltest';
 CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH

--- a/mysql-test/r/innodb_gis.result
+++ b/mysql-test/r/innodb_gis.result
@@ -403,7 +403,7 @@ Intersects(g1.g, g2.g) as i, Crosses(g1.g, g2.g) as r
 FROM gis_geometrycollection g1, gis_geometrycollection g2 ORDER BY first, second;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	g1	ALL	NULL	NULL	NULL	NULL	2	100.00	Using temporary; Using filesort
-1	SIMPLE	g2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
+1	SIMPLE	g2	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`g1`.`fid` AS `first`,`test`.`g2`.`fid` AS `second`,within(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `w`,contains(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `c`,overlaps(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `o`,equals(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `e`,disjoint(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `d`,touches(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `t`,intersects(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `i`,crosses(`test`.`g1`.`g`,`test`.`g2`.`g`) AS `r` from `test`.`gis_geometrycollection` `g1` join `test`.`gis_geometrycollection` `g2` order by `test`.`g1`.`fid`,`test`.`g2`.`fid`
 DROP TABLE gis_point, gis_line, gis_polygon, gis_multi_point, gis_multi_line, gis_multi_polygon, gis_geometrycollection, gis_geometry;

--- a/mysql-test/r/innodb_mysql.result
+++ b/mysql-test/r/innodb_mysql.result
@@ -187,7 +187,7 @@ min(7)
 explain select min(7) from t2i join t1i;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2i	ALL	NULL	NULL	NULL	NULL	1	
-1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer
+1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
 select min(7) from t2i join t1i;
 min(7)
 NULL
@@ -203,7 +203,7 @@ max(7)
 explain select max(7) from t2i join t1i;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2i	ALL	NULL	NULL	NULL	NULL	1	
-1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer
+1	SIMPLE	t1i	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
 select max(7) from t2i join t1i;
 max(7)
 NULL

--- a/mysql-test/r/join.result
+++ b/mysql-test/r/join.result
@@ -404,7 +404,7 @@ SELECT STRAIGHT_JOIN t2.e FROM t1,t2 WHERE t2.d=1 AND t1.b=t2.e
 ORDER BY t1.b, t1.c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	32	Using temporary; Using filesort
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	16	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	16	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN t2.e FROM t1,t2 WHERE t2.d=1 AND t1.b=t2.e
 ORDER BY t1.b, t1.c;
 e
@@ -1099,7 +1099,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	0	Using where
 1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	0	Using where
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	0	Using where
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using where; Using join buffer (flat, BNL join)
 SELECT * 
 FROM 
 t1 JOIN t2 ON t1.a = t2.a 

--- a/mysql-test/r/join_cache.result
+++ b/mysql-test/r/join_cache.result
--- a/mysql-test/r/join_nested.result
+++ b/mysql-test/r/join_nested.result
--- a/mysql-test/r/join_nested_jcl6.result
+++ b/mysql-test/r/join_nested_jcl6.result
--- a/mysql-test/r/join_outer_jcl6.result
+++ b/mysql-test/r/join_outer_jcl6.result
@@ -102,7 +102,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 explain select t1.*,t2.* from t1 left join t2 on t1.a=t2.a where isnull(t2.a)=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	7	
-1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	8	test.t1.a	1	Using where; Using join buffer
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	8	test.t1.a	1	Using where; Using join buffer (flat, BKA join)
 select t1.*,t2.*,t3.a from t1 left join t2 on (t1.a=t2.a) left join t1 as t3 on (t2.a=t3.a);
 grp	a	c	id	a	c	d	a
 1	1	a	1	1	a	1	1
@@ -319,11 +319,11 @@ Lilliana Angelovska	NULL	NULL
 explain select t1.name, t2.name, t2.id from t1 left join t2 on (t1.id = t2.owner) where t2.id is null;
 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	3	Using where; Not exists; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists; Using join buffer (flat, BNL join)
 explain select t1.name, t2.name, t2.id from t1 left join t2 on (t1.id = t2.owner) where t2.name is null;
 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	3	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 select count(*) from t1 left join t2 on (t1.id = t2.owner);
 count(*)
 4
@@ -339,11 +339,11 @@ Lilliana Angelovska	NULL	NULL
 explain select t1.name, t2.name, t2.id from t2 right join t1 on (t1.id = t2.owner) where t2.id is null;
 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	3	Using where; Not exists; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists; Using join buffer (flat, BNL join)
 explain select t1.name, t2.name, t2.id from t2 right join t1 on (t1.id = t2.owner) where t2.name is null;
 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	3	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 select count(*) from t2 right join t1 on (t1.id = t2.owner);
 count(*)
 4
@@ -695,8 +695,8 @@ a1	a2	b1	b2	c1	c2
 explain select * from t1 left join t2  on  b1 = a1 left join t3  on  c1 = a1  and  b1 is null;
 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	2	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (incremental, BNL join)
 drop table t1, t2, t3;
 create table t1 (
 a int(11),
@@ -745,13 +745,13 @@ explain select s.*, '*', m.*, (s.match_1_h - m.home) UUX from
 order by m.match_id desc;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	s	ALL	NULL	NULL	NULL	NULL	10	Using temporary; Using filesort
-1	SIMPLE	m	const	match_id,match_id_2	match_id	1	const	1	Using join buffer
+1	SIMPLE	m	const	match_id,match_id_2	match_id	1	const	1	Using join buffer (flat, BKA join)
 explain select s.*, '*', m.*, (s.match_1_h - m.home) UUX from 
 (t2 s left join t1 m on m.match_id = 1) 
 order by UUX desc;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	s	ALL	NULL	NULL	NULL	NULL	10	Using temporary; Using filesort
-1	SIMPLE	m	const	match_id,match_id_2	match_id	1	const	1	Using join buffer
+1	SIMPLE	m	const	match_id,match_id_2	match_id	1	const	1	Using join buffer (flat, BKA join)
 select s.*, '*', m.*, (s.match_1_h - m.home) UUX from 
 (t2 s left join t1 m on m.match_id = 1) 
 order by UUX desc;
@@ -771,7 +771,7 @@ t2 s straight_join t1 m where m.match_id = 1
 order by UUX desc;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	s	ALL	NULL	NULL	NULL	NULL	10	Using temporary; Using filesort
-1	SIMPLE	m	const	match_id,match_id_2	match_id	1	const	1	Using join buffer
+1	SIMPLE	m	const	match_id,match_id_2	match_id	1	const	1	Using join buffer (flat, BKA join)
 select s.*, '*', m.*, (s.match_1_h - m.home) UUX from 
 t2 s straight_join t1 m where m.match_id = 1 
 order by UUX desc;
@@ -1134,15 +1134,15 @@ a	b	a	b
 EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t1.a = t2.a WHERE t1.a = t2.a OR t1.a = t2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	4	Using where
-1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using join buffer
+1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using join buffer (flat, BKA join)
 EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t1.a = t2.a WHERE t1.a IN(t2.a, t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	4	Using where
-1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using join buffer
+1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using join buffer (flat, BKA join)
 EXPLAIN SELECT * FROM t1 LEFT JOIN t2 ON t1.a = t2.a WHERE t1.a > IF(t1.a = t2.b-2, t2.b, t2.b-1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	4	Using where
-1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using join buffer
+1	SIMPLE	t1	eq_ref	PRIMARY	PRIMARY	4	test.t2.a	1	Using join buffer (flat, BKA join)
 DROP TABLE t1,t2;
 DROP VIEW IF EXISTS v1,v2;
 DROP TABLE IF EXISTS t1,t2;
@@ -1231,7 +1231,7 @@ EXPLAIN
 SELECT t1.id, a FROM t1 LEFT JOIN t2 ON t1.id=t2.id WHERE t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	
-1	SIMPLE	t2	ref	idx	idx	4	test.t1.id	2	Using where; Not exists; Using join buffer
+1	SIMPLE	t2	ref	idx	idx	4	test.t1.id	2	Using where; Not exists; Using join buffer (flat, BKA join)
 flush status;
 SELECT t1.id, a FROM t1 LEFT JOIN t2 ON t1.id=t2.id WHERE t2.b IS NULL;
 id	a

--- a/mysql-test/r/key_diff.result
+++ b/mysql-test/r/key_diff.result
@@ -36,7 +36,7 @@ a	a	a	a
 explain select t1.*,t2.* from t1,t1 as t2 where t1.A=t2.B;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	
-1	SIMPLE	t2	ALL	b	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t2	ALL	b	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 select t1.*,t2.* from t1,t1 as t2 where t1.A=t2.B order by binary t1.a,t2.a;
 a	b	a	b
 A	B	a	a

--- a/mysql-test/r/myisam.result
+++ b/mysql-test/r/myisam.result
@@ -346,11 +346,11 @@ t1	1	c_2	2	a	A	5	NULL	NULL		BTREE
 explain select * from t1,t2 where t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 explain select * from t1,t2 force index(a) where t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 explain select * from t1 force index(a),t2 force index(a) where t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	2	
@@ -362,7 +362,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 explain select * from t1,t2 force index(c) where t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 explain select * from t1 where a=0 or a=2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	5	Using where

--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -1608,18 +1608,18 @@ EXPLAIN
 SELECT * FROM t1 FORCE INDEX FOR ORDER BY (a), t2 WHERE t1.a < 2 ORDER BY t1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	a	a	5	NULL	2	Using index condition; Using MRR; Using temporary; Using filesort
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 # should have "using filesort"
 EXPLAIN 
 SELECT * FROM t1 USE INDEX FOR ORDER BY (a), t2 WHERE t1.a < 2 ORDER BY t1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	a	a	5	NULL	2	Using index condition; Using MRR; Using temporary; Using filesort
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 # should have "using filesort"
 EXPLAIN 
 SELECT * FROM t1 FORCE INDEX FOR JOIN (a), t2 WHERE t1.a < 2 ORDER BY t1.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	a	a	5	NULL	2	Using index condition; Using MRR; Using temporary; Using filesort
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	10	Using join buffer (flat, BNL join)
 DROP TABLE t1, t2;
 End of 5.1 tests
--- a/mysql-test/r/pool_of_threads.result
+++ b/mysql-test/r/pool_of_threads.result
@@ -1429,7 +1429,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008

--- a/mysql-test/r/range.result
+++ b/mysql-test/r/range.result
@@ -221,27 +221,27 @@ update t1 set y=x;
 explain select * from t1, t1 t2 where t1.y = 8 and t2.x between 7 and t1.y+0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 8 and t2.x >= 7 and t2.x <= t1.y+0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	3	Using index condition; Using MRR; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	3	Using index condition; Using MRR; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	3	Using index condition; Using MRR; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	3	Using index condition; Using MRR; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	2	Using index condition; Using MRR; Using join buffer (flat, BNL join)
 explain select count(*) from t1 where x in (1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	x	x	5	const	1	Using index
@@ -256,12 +256,12 @@ INSERT INTO t2 VALUES (0),(0),(1),(1),(2),(2);
 explain select * from t1, t2 where (t1.key1 <t2.keya + 1) and t2.keya=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	j1	j1	4	const	1	Using index
-1	SIMPLE	t1	index	i1	i1	4	NULL	7	Using where; Using index; Using join buffer
+1	SIMPLE	t1	index	i1	i1	4	NULL	7	Using where; Using index; Using join buffer (flat, BNL join)
 explain select * from t1 force index(i1), t2 force index(j1) where 
 (t1.key1 <t2.keya + 1) and t2.keya=3;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	j1	j1	4	const	1	Using index
-1	SIMPLE	t1	index	i1	i1	4	NULL	7	Using where; Using index; Using join buffer
+1	SIMPLE	t1	index	i1	i1	4	NULL	7	Using where; Using index; Using join buffer (flat, BNL join)
 DROP TABLE t1,t2;
 CREATE TABLE t1 (
 a int(11) default NULL,

--- a/mysql-test/r/row.result
+++ b/mysql-test/r/row.result
@@ -377,7 +377,7 @@ a	b	a	b	c
 EXPLAIN EXTENDED SELECT * FROM t1,t2 WHERE (t1.a-1,t1.b)=(t2.a-1,t2.b+1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	index	NULL	PRIMARY	8	NULL	6	100.00	Using index
-1	SIMPLE	t2	index	NULL	PRIMARY	12	NULL	7	100.00	Using where; Using index; Using join buffer
+1	SIMPLE	t2	index	NULL	PRIMARY	12	NULL	7	100.00	Using where; Using index; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t1` join `test`.`t2` where (((`test`.`t1`.`a` - 1) = (`test`.`t2`.`a` - 1)) and (`test`.`t1`.`b` = (`test`.`t2`.`b` + 1)))
 SELECT * FROM t1,t2 WHERE (t1.a-1,t1.b)=(t2.a-1,t2.b+1);

--- a/mysql-test/r/select.result
+++ b/mysql-test/r/select.result
@@ -1431,7 +1431,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008
@@ -2363,7 +2363,7 @@ insert into t2 values (1,3), (2,3), (3,4), (4,4);
 explain select * from t1 left join t2 on a=c where d in (4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	c,d	d	5	const	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 select * from t1 left join t2 on a=c where d in (4);
 a	b	c	d
 3	2	3	4
@@ -2371,7 +2371,7 @@ a	b	c	d
 explain select * from t1 left join t2 on a=c where d = 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	c,d	d	5	const	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 select * from t1 left join t2 on a=c where d = 4;
 a	b	c	d
 3	2	3	4
@@ -2717,7 +2717,7 @@ where (t1.c=t2.a or (t1.c=t3.a and t2.a=t3.b)) and t1.b=556476786 and
 t2.b like '%%' order by t2.b limit 0,1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	b,c	b	5	const	1	Using temporary; Using filesort
-1	SIMPLE	t3	index	PRIMARY,a,b	PRIMARY	8	NULL	2	Using index; Using join buffer
+1	SIMPLE	t3	index	PRIMARY,a,b	PRIMARY	8	NULL	2	Using index; Using join buffer (flat, BNL join)
 1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	2	Range checked for each record (index map: 0x1)
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a int, INDEX idx(a));
@@ -2738,7 +2738,7 @@ ALTER TABLE t1 ENABLE KEYS;
 EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	b	b	5	NULL	2	Using index
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 a	b	a	b
 1	NULL	1	1
@@ -2748,7 +2748,7 @@ a	b	a	b
 EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	b	b	5	NULL	2	Using index
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 a	b	a	b
 1	NULL	1	1
@@ -2910,11 +2910,11 @@ a
 EXPLAIN SELECT t1.a FROM t1 STRAIGHT_JOIN t2 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	5	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 EXPLAIN SELECT t1.a FROM t1 INNER JOIN t2 ON t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 DROP TABLE t1,t2;
 select x'10' + 0, X'10' + 0, b'10' + 0, B'10' + 0;
 x'10' + 0	X'10' + 0	b'10' + 0	B'10' + 0

--- a/mysql-test/r/select_jcl6.result
+++ b/mysql-test/r/select_jcl6.result
--- a/mysql-test/r/select_pkeycache.result
+++ b/mysql-test/r/select_pkeycache.result
@@ -1431,7 +1431,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008
@@ -2363,7 +2363,7 @@ insert into t2 values (1,3), (2,3), (3,4), (4,4);
 explain select * from t1 left join t2 on a=c where d in (4);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	c,d	d	5	const	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 select * from t1 left join t2 on a=c where d in (4);
 a	b	c	d
 3	2	3	4
@@ -2371,7 +2371,7 @@ a	b	c	d
 explain select * from t1 left join t2 on a=c where d = 4;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ref	c,d	d	5	const	2	
-1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t1	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 select * from t1 left join t2 on a=c where d = 4;
 a	b	c	d
 3	2	3	4
@@ -2717,7 +2717,7 @@ where (t1.c=t2.a or (t1.c=t3.a and t2.a=t3.b)) and t1.b=556476786 and
 t2.b like '%%' order by t2.b limit 0,1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	b,c	b	5	const	1	Using temporary; Using filesort
-1	SIMPLE	t3	index	PRIMARY,a,b	PRIMARY	8	NULL	2	Using index; Using join buffer
+1	SIMPLE	t3	index	PRIMARY,a,b	PRIMARY	8	NULL	2	Using index; Using join buffer (flat, BNL join)
 1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	2	Range checked for each record (index map: 0x1)
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a int, INDEX idx(a));
@@ -2738,7 +2738,7 @@ ALTER TABLE t1 ENABLE KEYS;
 EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	b	b	5	NULL	2	Using index
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 a	b	a	b
 1	NULL	1	1
@@ -2748,7 +2748,7 @@ a	b	a	b
 EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	b	b	5	NULL	2	Using index
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 a	b	a	b
 1	NULL	1	1
@@ -2910,11 +2910,11 @@ a
 EXPLAIN SELECT t1.a FROM t1 STRAIGHT_JOIN t2 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	5	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 EXPLAIN SELECT t1.a FROM t1 INNER JOIN t2 ON t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 DROP TABLE t1,t2;
 select x'10' + 0, X'10' + 0, b'10' + 0, B'10' + 0;
 x'10' + 0	X'10' + 0	b'10' + 0	B'10' + 0

--- a/mysql-test/r/ssl.result
+++ b/mysql-test/r/ssl.result
@@ -1432,7 +1432,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008

--- a/mysql-test/r/ssl_compress.result
+++ b/mysql-test/r/ssl_compress.result
@@ -1435,7 +1435,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1199	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008

--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -906,7 +906,7 @@ explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) F
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
 2	DEPENDENT SUBQUERY	t2	ref_or_null	a	a	5	func	2	100.00	Using index
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer
+2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
 drop table t1,t2,t3;
@@ -1296,7 +1296,7 @@ a
 explain extended select * from t2 where t2.a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer
+1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where (`test`.`t1`.`a` = `test`.`t2`.`a`)
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
@@ -1306,7 +1306,7 @@ a
 explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
@@ -1316,7 +1316,7 @@ 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	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))

--- a/mysql-test/r/subselect3.result
+++ b/mysql-test/r/subselect3.result
--- a/mysql-test/r/subselect3_jcl6.result
+++ b/mysql-test/r/subselect3_jcl6.result
--- a/mysql-test/r/subselect4.result
+++ b/mysql-test/r/subselect4.result
@@ -51,7 +51,7 @@ FROM t3 WHERE 1 = 0 GROUP BY 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	DEPENDENT SUBQUERY	t1	index	NULL	PRIMARY	4	NULL	2	Using index
-2	DEPENDENT SUBQUERY	t2	index	b	b	5	NULL	2	Using where; Using index; Using join buffer
+2	DEPENDENT SUBQUERY	t2	index	b	b	5	NULL	2	Using where; Using index; Using join buffer (flat, BNL join)
 # should return 0 rows
 SELECT
 (SELECT 1 FROM t1,t2 WHERE t2.b > t3.b)
@@ -218,7 +218,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
 1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 PREPARE stmt FROM "EXPLAIN SELECT EMPNAME
 FROM t1
 WHERE EMPNUM IN
@@ -233,13 +233,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
 1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
 1	SIMPLE	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 DEALLOCATE PREPARE stmt;
 DROP INDEX t1_IDX ON t1;
 CREATE INDEX t1_IDX ON t1(EMPNUM);
@@ -256,7 +256,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
 1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 PREPARE stmt FROM "EXPLAIN SELECT EMPNAME
 FROM t1
 WHERE EMPNUM IN
@@ -271,13 +271,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
 1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	t1_IDX	NULL	NULL	NULL	5	
 1	SIMPLE	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 DEALLOCATE PREPARE stmt;
 DROP INDEX t1_IDX ON t1;
 EXPLAIN SELECT EMPNAME
@@ -293,7 +293,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
 1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 PREPARE stmt FROM "EXPLAIN SELECT EMPNAME
 FROM t1
 WHERE EMPNUM IN
@@ -308,13 +308,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	
 1	PRIMARY	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 EXECUTE stmt;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	
 1	SIMPLE	subselect2	eq_ref	unique_key	unique_key	3	func	1	
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	6	Using where
-2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer
+2	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	12	Using where; Using join buffer (flat, BNL join)
 DEALLOCATE PREPARE stmt;
 SET SESSION optimizer_switch = @old_optimizer_switch;
 SET SESSION join_cache_level = @old_join_cache_level;

--- a/mysql-test/r/subselect_mat.result
+++ b/mysql-test/r/subselect_mat.result
@@ -423,7 +423,7 @@ where (c1, c2) in (select b1, b2 from t2i where b2 > '0')) and
 a1 = c1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where; Using join buffer
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where; Using join buffer (flat, BNL join)
 4	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 5	SUBQUERY	t2i	index	it2i2	it2i3	18	NULL	5	100.00	Using where; Using index
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
@@ -659,7 +659,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 2	DEPENDENT SUBQUERY	t1_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 3	DEPENDENT SUBQUERY	t2_16	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
-3	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer
+3	DEPENDENT SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Using join buffer (flat, BNL join)
 4	SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where <in_optimizer>(concat(`test`.`t1`.`a1`,'x'),<exists>(select 1 from `test`.`t1_16` where (<in_optimizer>((`test`.`t1_16`.`a1`,`test`.`t1_16`.`a2`),<exists>(select `test`.`t2_16`.`b1`,`test`.`t2_16`.`b2` from `test`.`t2_16` join `test`.`t2` where ((`test`.`t2`.`b2` = substr(`test`.`t2_16`.`b2`,1,6)) and <in_optimizer>(`test`.`t2`.`b1`,`test`.`t2`.`b1` in ( <materialize> (select `test`.`t3`.`c1` from `test`.`t3` where (`test`.`t3`.`c2` > '0') ), <primary_index_lookup>(`test`.`t2`.`b1` in <temporary table> on distinct_key where ((`test`.`t2`.`b1` = `materialized subselect`.`c1`))))) and (<cache>(`test`.`t1_16`.`a1`) = `test`.`t2_16`.`b1`) and (<cache>(`test`.`t1_16`.`a2`) = `test`.`t2_16`.`b2`)))) and (<cache>(concat(`test`.`t1`.`a1`,'x')) = left(`test`.`t1_16`.`a1`,8)))))
@@ -1191,7 +1191,7 @@ SET @@optimizer_switch='default,semijoin=on,materialization=on';
 EXPLAIN SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	2	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	t2	ALL	NULL	NULL	NULL	NULL	2	
 SELECT COUNT(*) FROM t1 WHERE (f1,f2) IN (SELECT f1,f2 FROM t2);
 COUNT(*)

--- a/mysql-test/r/subselect_no_mat.result
+++ b/mysql-test/r/subselect_no_mat.result
@@ -910,7 +910,7 @@ explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) F
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
 2	DEPENDENT SUBQUERY	t2	ref_or_null	a	a	5	func	2	100.00	Using index
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer
+2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
 drop table t1,t2,t3;
@@ -1300,7 +1300,7 @@ a
 explain extended select * from t2 where t2.a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer
+1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where (`test`.`t1`.`a` = `test`.`t2`.`a`)
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
@@ -1310,7 +1310,7 @@ a
 explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
@@ -1320,7 +1320,7 @@ 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	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))

--- a/mysql-test/r/subselect_no_opts.result
+++ b/mysql-test/r/subselect_no_opts.result
@@ -907,7 +907,7 @@ explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) F
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
 2	DEPENDENT SUBQUERY	t2	ref_or_null	a	a	5	func	2	100.00	Using index
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer
+2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
 drop table t1,t2,t3;
@@ -1361,7 +1361,7 @@ explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	DEPENDENT SUBQUERY	t1	ref	a	a	5	func	1001	100.00	Using index
-2	DEPENDENT SUBQUERY	t3	index	a	a	5	NULL	3	100.00	Using where; Using index; Using join buffer
+2	DEPENDENT SUBQUERY	t3	index	a	a	5	NULL	3	100.00	Using where; Using index; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,<exists>(select 1 from `test`.`t1` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t1`.`b`) and (<cache>(`test`.`t2`.`a`) = `test`.`t1`.`a`))))
 insert into t1 values (3,31);

--- a/mysql-test/r/subselect_no_semijoin.result
+++ b/mysql-test/r/subselect_no_semijoin.result
@@ -907,7 +907,7 @@ explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) F
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
 2	DEPENDENT SUBQUERY	t2	ref_or_null	a	a	5	func	2	100.00	Using index
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer
+2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
 drop table t1,t2,t3;
@@ -1318,7 +1318,7 @@ explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	PRIMARY	4	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t3	index	PRIMARY	PRIMARY	4	NULL	3	100.00	Using index
-2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where; Using join buffer
+2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	4	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` from `test`.`t1` join `test`.`t3` where (`test`.`t1`.`b` = `test`.`t3`.`a`) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `materialized subselect`.`a`)))))
 drop table t1, t2, t3;
@@ -1361,7 +1361,7 @@ explain extended select * from t2 where t2.a in (select t1.a from t1,t3 where t1
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	NULL	a	5	NULL	4	100.00	Using where; Using index
 2	SUBQUERY	t3	index	a	a	5	NULL	3	100.00	Using index
-2	SUBQUERY	t1	index	NULL	a	10	NULL	10004	100.00	Using where; Using index; Using join buffer
+2	SUBQUERY	t1	index	NULL	a	10	NULL	10004	100.00	Using where; Using index; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t2` where <in_optimizer>(`test`.`t2`.`a`,`test`.`t2`.`a` in ( <materialize> (select `test`.`t1`.`a` from `test`.`t1` join `test`.`t3` where (`test`.`t1`.`b` = `test`.`t3`.`a`) ), <primary_index_lookup>(`test`.`t2`.`a` in <temporary table> on distinct_key where ((`test`.`t2`.`a` = `materialized subselect`.`a`)))))
 insert into t1 values (3,31);

--- a/mysql-test/r/subselect_sj.result
+++ b/mysql-test/r/subselect_sj.result
--- a/mysql-test/r/subselect_sj2.result
+++ b/mysql-test/r/subselect_sj2.result
@@ -130,7 +130,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	22	
-1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer
+1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
@@ -198,7 +198,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	22	
-1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer
+1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
@@ -272,7 +272,7 @@ from t0 where a in
 (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	Start temporary
-1	PRIMARY	t1	index	NULL	a	5	NULL	10	Using index; Using join buffer
+1	PRIMARY	t1	index	NULL	a	5	NULL	10	Using index; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ref	a	a	5	test.t1.a	1	Using where; Using index
 1	PRIMARY	t3	ref	a	a	5	test.t1.a	1	Using where; Using index; End temporary
 drop table t0, t1,t2,t3;

--- a/mysql-test/r/subselect_sj2_jcl6.result
+++ b/mysql-test/r/subselect_sj2_jcl6.result
@@ -40,7 +40,7 @@ a	b
 explain select * from t2 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	3	
-1	PRIMARY	t2	ref	b	b	5	test.t1.a	2	Using join buffer
+1	PRIMARY	t2	ref	b	b	5	test.t1.a	2	Using join buffer (flat, BKA join)
 2	SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
 select * from t2 where b in (select a from t1);
 a	b
@@ -59,7 +59,7 @@ insert into t3 select a,a, a,a,a from t0;
 explain select * from t3 where b in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	ALL	b	NULL	NULL	NULL	10	
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; FirstMatch(t3); Using join buffer
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; FirstMatch(t3); Using join buffer (flat, BNL join)
 select * from t3 where b in (select a from t1);
 a	b	pk1	pk2	pk3
 1	1	1	1	1
@@ -82,7 +82,7 @@ from t0 A, t0 B where B.a <5;
 explain select * from t3 where b in (select a from t0);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	10	
-1	PRIMARY	t3	ref	b	b	5	test.t0.a	1	Using join buffer
+1	PRIMARY	t3	ref	b	b	5	test.t0.a	1	Using join buffer (flat, BKA join)
 2	SUBQUERY	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
 set @save_ecp= @@engine_condition_pushdown;
 set engine_condition_pushdown=0;
@@ -137,7 +137,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	22	
-1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer
+1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	32	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
@@ -205,7 +205,7 @@ a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z
 from t1 ot where a in (select a from t2 it);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	subselect2	ALL	unique_key	NULL	NULL	NULL	22	
-1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer
+1	PRIMARY	ot	ALL	NULL	NULL	NULL	NULL	52	Using where; Using join buffer (flat, BNL join)
 2	SUBQUERY	it	ALL	NULL	NULL	NULL	NULL	22	
 select 
 a, mid(filler1, 1,10), length(filler1)=length(filler2) as Z 
@@ -279,7 +279,7 @@ from t0 where a in
 (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	10	Start temporary
-1	PRIMARY	t1	index	NULL	a	5	NULL	10	Using index; Using join buffer
+1	PRIMARY	t1	index	NULL	a	5	NULL	10	Using index; Using join buffer (flat, BNL join)
 1	PRIMARY	t2	ref	a	a	5	test.t1.a	1	Using where; Using index
 1	PRIMARY	t3	ref	a	a	5	test.t1.a	1	Using where; Using index; End temporary
 drop table t0, t1,t2,t3;
@@ -318,8 +318,8 @@ WHERE Language='English' AND Percentage > 10 AND
 t2.Population > 100000);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	range	Population,Country	Population	4	NULL	1	Using index condition; Using MRR
-1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where; Using join buffer
+1	PRIMARY	t3	eq_ref	PRIMARY,Percentage	PRIMARY	33	test.t1.Country,const	1	Using index condition; Using where; Using join buffer (flat, BKA join)
-1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t3.Country	1	Using index condition(BKA); Using where; Using join buffer
+1	PRIMARY	t2	eq_ref	PRIMARY,Population	PRIMARY	3	test.t3.Country	1	Using index condition(BKA); Using where; Using join buffer (incremental, BKA join)
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (
 Code char(3) NOT NULL DEFAULT '',
@@ -433,8 +433,8 @@ where t0.a in ( select t1.a from t1,t2 where t2.a=t0.a and
 t1.b=t2.b);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t0	ALL	NULL	NULL	NULL	NULL	5	100.00	Using where; Start temporary
-1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Using join buffer
+1	PRIMARY	t1	ref	a	a	5	test.t0.a	1	100.00	Using join buffer (flat, BKA join)
-1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	Using where; End temporary; Using join buffer
+1	PRIMARY	t2	eq_ref	PRIMARY	PRIMARY	4	test.t0.a	1	100.00	Using where; End temporary; Using join buffer (incremental, BKA join)
 Warnings:
 Note	1276	Field or reference 'test.t0.a' of SELECT #2 was resolved in SELECT #1
 Note	1003	select `test`.`t0`.`a` AS `a` from `test`.`t2` semi join (`test`.`t1`) join `test`.`t0` where ((`test`.`t2`.`b` = `test`.`t1`.`b`) and (`test`.`t1`.`a` = `test`.`t0`.`a`) and (`test`.`t2`.`a` = `test`.`t0`.`a`))
@@ -587,7 +587,7 @@ explain
 select * from t1 left join t2 on (t2.a= t1.a and t2.a in (select pk from t3));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	3	
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t3	unique_subquery	PRIMARY	PRIMARY	4	func	1	Using index
 drop table t0, t1, t2, t3;
 create table t1 (a int);
@@ -728,9 +728,9 @@ c2 in (select 1 from t3, t2) and
 c1 in (select convert(c6,char(1)) from t2);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using join buffer
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using join buffer (flat, BNL join)
-1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; Using join buffer
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	Using where; Using join buffer (incremental, BNL join)
-1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch(t2); Using join buffer
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	2	FirstMatch(t2); Using join buffer (incremental, BNL join)
 drop table t2, t3;
 set join_cache_level=default;
 show variables like 'join_cache_level';

--- a/mysql-test/r/subselect_sj_jcl6.result
+++ b/mysql-test/r/subselect_sj_jcl6.result
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -542,7 +542,7 @@ explain (select * from t1 where a=1 and b=10) union (select straight_join t1.a,t
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	UNION	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index
-2	UNION	t2	index	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index; Using join buffer
+2	UNION	t2	index	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index; Using join buffer (flat, BNL join)
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 explain (select * from t1 where a=1) union (select * from t1 where b=1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -2350,7 +2350,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT * FROM v2 WHERE a=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	a	a	5	const	1	Using index
-1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 DROP VIEW v1,v2;
 DROP TABLE t1,t2,t3;
 create table t1 (f1 int);

--- a/mysql-test/suite/pbxt/r/derived.result
+++ b/mysql-test/suite/pbxt/r/derived.result
@@ -58,7 +58,7 @@ a	b	a	b
 explain select * from t1 as x1, (select * from t1) as x2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	x1	ALL	NULL	NULL	NULL	NULL	4	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	4	Using join buffer (flat, BNL join)
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	4	
 drop table if exists  t2,t3;
 select * from (select 1) as a;
@@ -115,7 +115,7 @@ explain select * from (select t1.*, t2.a as t2a from t1,t2 where t1.a=t2.a) t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	
 2	DERIVED	t2	ALL	NULL	NULL	NULL	NULL	1	
-2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer
+2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 drop table t1, t2;
 create table t1(a int not null, t char(8), index(a));
 SELECT * FROM (SELECT * FROM t1) as b ORDER BY a  ASC LIMIT 0,20;
@@ -143,7 +143,7 @@ a	t
 explain select count(*) from t1 as tt1, (select * from t1) as tt2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	tt1	index	NULL	a	4	NULL	10000	Using index
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	10000	Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	10000	Using join buffer (flat, BNL join)
 2	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	10000	
 drop table t1;
 SELECT * FROM (SELECT (SELECT * FROM (SELECT 1 as a) as a )) as b;
@@ -190,13 +190,13 @@ pla_id	test
 explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	m2	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 2	DERIVED	mp	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
 2	DERIVED	m1	eq_ref	PRIMARY	PRIMARY	3	test.mp.mat_id	1	
 explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2  INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	m2	ALL	NULL	NULL	NULL	NULL	9	
-1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	6	Using where; Using join buffer (flat, BNL join)
 2	DERIVED	mp	ALL	NULL	NULL	NULL	NULL	9	Using temporary; Using filesort
 2	DERIVED	m1	eq_ref	PRIMARY	PRIMARY	3	test.mp.mat_id	1	
 drop table t1,t2;
@@ -250,7 +250,7 @@ a	a
 explain select * from ( select * from t1 union select * from t1) a,(select * from t1 union select * from t1) b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	2	
-1	PRIMARY	<derived4>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer
+1	PRIMARY	<derived4>	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 4	DERIVED	t1	ALL	NULL	NULL	NULL	NULL	2	
 5	UNION	t1	ALL	NULL	NULL	NULL	NULL	2	
 NULL	UNION RESULT	<union4,5>	ALL	NULL	NULL	NULL	NULL	NULL	
@@ -317,7 +317,7 @@ explain SELECT s.name, AVG(s.val) AS median FROM (SELECT x.name, x.val FROM t1 x
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	3	Using temporary; Using filesort
 2	DERIVED	x	ALL	NULL	NULL	NULL	NULL	17	Using temporary; Using filesort
-2	DERIVED	y	ALL	NULL	NULL	NULL	NULL	17	Using where; Using join buffer
+2	DERIVED	y	ALL	NULL	NULL	NULL	NULL	17	Using where; Using join buffer (flat, BNL join)
 drop table t1;
 create table t2 (a int, b int, primary key (a));
 insert into t2 values (1,7),(2,7);

--- a/mysql-test/suite/pbxt/r/distinct.result
+++ b/mysql-test/suite/pbxt/r/distinct.result
@@ -300,11 +300,11 @@ WHERE
 AND ((t1.id=j_lj_t3.id AND t3_lj.id IS NULL) OR (t1.id=t3.id AND t3.idx=2));
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	id	id	4	NULL	2	Using index; Using temporary
-1	SIMPLE	t2	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer
+1	SIMPLE	t2	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer (flat, BNL join)
-1	SIMPLE	t3	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer
+1	SIMPLE	t3	index	id	id	8	NULL	1	Using index; Distinct; Using join buffer (flat, BNL join)
-1	SIMPLE	j_lj_t2	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer
+1	SIMPLE	j_lj_t2	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer (flat, BNL join)
 1	SIMPLE	t2_lj	ref	id	id	4	test.j_lj_t2.id	1	Using where; Using index; Distinct
-1	SIMPLE	j_lj_t3	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer
+1	SIMPLE	j_lj_t3	index	id	id	4	NULL	2	Using where; Using index; Distinct; Using join buffer (flat, BNL join)
 1	SIMPLE	t3_lj	ref	id	id	4	test.j_lj_t3.id	1	Using where; Using index; Distinct
 SELECT DISTINCT
 t1.id
@@ -515,7 +515,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1_1	ALL	NULL	NULL	NULL	NULL	3	Using temporary
-1	SIMPLE	t1_2	index	NULL	PRIMARY	4	NULL	3	Using index; Distinct; Using join buffer
+1	SIMPLE	t1_2	index	NULL	PRIMARY	4	NULL	3	Using index; Distinct; Using join buffer (flat, BNL join)
 EXPLAIN SELECT DISTINCT t1_1.a, t1_1.b FROM t1 t1_1, t1 t1_2
 WHERE t1_1.a = t1_2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

--- a/mysql-test/suite/pbxt/r/func_group.result
+++ b/mysql-test/suite/pbxt/r/func_group.result
@@ -614,7 +614,7 @@ explain
 select max(t1.a3), min(t2.a2) from t1, t2 where t1.a2 = 2 and t1.a3 < 'MIN' and t2.a3 > 'CA';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	k1	k1	7	NULL	1	Using where; Using index
-1	SIMPLE	t2	range	k1	k1	3	NULL	1	Using where; Using index; Using join buffer
+1	SIMPLE	t2	range	k1	k1	3	NULL	1	Using where; Using index; Using join buffer (flat, BNL join)
 explain
 select min(a4 - 0.01) from t1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
@@ -651,7 +651,7 @@ explain
 select concat(min(t1.a1),min(t2.a4)) from t1, t2 where t2.a4 <> 'AME';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	k2	k2	4	NULL	7	Using where; Using index
-1	SIMPLE	t1	index	NULL	PRIMARY	3	NULL	15	Using index; Using join buffer
+1	SIMPLE	t1	index	NULL	PRIMARY	3	NULL	15	Using index; Using join buffer (flat, BNL join)
 drop table t1, t2;
 create table t1 (a char(10));
 insert into t1 values ('a'),('b'),('c');

--- a/mysql-test/suite/pbxt/r/greedy_optimizer.result
+++ b/mysql-test/suite/pbxt/r/greedy_optimizer.result
--- a/mysql-test/suite/pbxt/r/group_by.result
+++ b/mysql-test/suite/pbxt/r/group_by.result
@@ -537,11 +537,11 @@ a	b
 explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary; Using filesort
-1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 explain select t1.a,t2.b from t1,t2 where t1.a=t2.a group by t1.a,t2.b ORDER BY NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	6	Using temporary
-1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer
+1	SIMPLE	t2	ALL	a	NULL	NULL	NULL	4	Using where; Using join buffer (flat, BNL join)
 drop table t1,t2;
 create table t1 (a int, b int);
 insert into t1 values (1, 4),(10, 40),(1, 4),(10, 43),(1, 4),(10, 41),(1, 4),(10, 43),(1, 4);

--- a/mysql-test/suite/pbxt/r/group_min_max.result
+++ b/mysql-test/suite/pbxt/r/group_min_max.result
@@ -2268,7 +2268,7 @@ 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_outer1	ref	a	a	5	const	1	Using where; Using index
-1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer
+1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using where; Using index; Using join buffer (flat, BNL join)
 2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
 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;

--- a/mysql-test/suite/pbxt/r/join_nested.result
+++ b/mysql-test/suite/pbxt/r/join_nested.result
--- a/mysql-test/suite/pbxt/r/range.result
+++ b/mysql-test/suite/pbxt/r/range.result
@@ -222,27 +222,27 @@ update t1 set y=x;
 explain select * from t1, t1 t2 where t1.y = 8 and t2.x between 7 and t1.y+0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 8 and t2.x >= 7 and t2.x <= t1.y+0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x between t1.y-1 and t1.y+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= t1.y-1 and t2.x <= t1.y+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer (flat, BNL join)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	
-1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer
+1	SIMPLE	t2	range	x	x	5	NULL	1	Using where; Using join buffer (flat, BNL join)
 explain select count(*) from t1 where x in (1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	x	x	5	const	1	Using index
@@ -422,20 +422,20 @@ test.t1	analyze	status	OK
 test.t2	analyze	status	OK
 explain select * from t1, t2  where t1.uid=t2.uid AND t1.uid > 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	uid_index	uid_index	4	NULL	1	Using where
+1	SIMPLE	t2	range	uid_index	uid_index	4	NULL	1	Using where
-1	SIMPLE	t2	ref	uid_index	uid_index	4	test.t1.uid	1	
+1	SIMPLE	t1	ref	uid_index	uid_index	4	test.t2.uid	1	
 explain select * from t1, t2  where t1.uid=t2.uid AND t2.uid > 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	uid_index	uid_index	4	NULL	1	Using where
+1	SIMPLE	t2	range	uid_index	uid_index	4	NULL	1	Using where
-1	SIMPLE	t2	ref	uid_index	uid_index	4	test.t1.uid	1	
+1	SIMPLE	t1	ref	uid_index	uid_index	4	test.t2.uid	1	
 explain select * from t1, t2  where t1.uid=t2.uid AND t1.uid != 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	uid_index	uid_index	4	NULL	2	Using where
+1	SIMPLE	t2	range	uid_index	uid_index	4	NULL	2	Using where
-1	SIMPLE	t2	ref	uid_index	uid_index	4	test.t1.uid	1	
+1	SIMPLE	t1	ref	uid_index	uid_index	4	test.t2.uid	1	
 explain select * from t1, t2  where t1.uid=t2.uid AND t2.uid != 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	uid_index	uid_index	4	NULL	2	Using where
+1	SIMPLE	t2	range	uid_index	uid_index	4	NULL	2	Using where
-1	SIMPLE	t2	ref	uid_index	uid_index	4	test.t1.uid	1	
+1	SIMPLE	t1	ref	uid_index	uid_index	4	test.t2.uid	1	
 select * from t1, t2  where t1.uid=t2.uid AND t1.uid > 0;
 id	name	uid	id	name	uid
 1001	A	1	1001	A	1

--- a/mysql-test/suite/pbxt/r/select.result
+++ b/mysql-test/suite/pbxt/r/select.result
@@ -1437,7 +1437,7 @@ companynr	companynr
 explain select distinct t2.companynr,t4.companynr from t2,t4 where t2.companynr=t4.companynr+1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t4	index	NULL	PRIMARY	1	NULL	12	Using index; Using temporary
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1200	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1200	Using where; Using join buffer (flat, BNL join)
 select t2.fld1,t2.companynr,fld3,period from t3,t2 where t2.fld1 = 38208 and t2.fld1=t3.t2nr and period = 1008 or t2.fld1 = 38008 and t2.fld1 =t3.t2nr and period = 1008;
 fld1	companynr	fld3	period
 038008	37	reporters	1008
@@ -2723,7 +2723,7 @@ where (t1.c=t2.a or (t1.c=t3.a and t2.a=t3.b)) and t1.b=556476786 and
 t2.b like '%%' order by t2.b limit 0,1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	b,c	b	5	const	1	Using temporary; Using filesort
-1	SIMPLE	t3	index	PRIMARY,a,b	PRIMARY	8	NULL	2	Using index; Using join buffer
+1	SIMPLE	t3	index	PRIMARY,a,b	PRIMARY	8	NULL	2	Using index; Using join buffer (flat, BNL join)
 1	SIMPLE	t2	ALL	PRIMARY	NULL	NULL	NULL	2	Range checked for each record (index map: 0x1)
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (a int, INDEX idx(a));
@@ -2746,7 +2746,7 @@ Note	1031	Table storage engine for 't1' doesn't have this option
 EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	b	b	5	NULL	2	Using index
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 a	b	a	b
 1	NULL	1	1
@@ -2756,7 +2756,7 @@ a	b	a	b
 EXPLAIN SELECT STRAIGHT_JOIN SQL_NO_CACHE COUNT(*) FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	index	b	b	5	NULL	2	Using index
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 SELECT STRAIGHT_JOIN SQL_NO_CACHE * FROM t2, t1 WHERE t1.b = t2.b OR t2.b IS NULL;
 a	b	a	b
 1	NULL	1	1
@@ -2910,11 +2910,11 @@ a
 EXPLAIN SELECT t1.a FROM t1 STRAIGHT_JOIN t2 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	5	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where; Using join buffer (flat, BNL join)
 EXPLAIN SELECT t1.a FROM t1 INNER JOIN t2 ON t1.a=t2.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	
-1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 DROP TABLE t1,t2;
 select x'10' + 0, X'10' + 0, b'10' + 0, B'10' + 0;
 x'10' + 0	X'10' + 0	b'10' + 0	B'10' + 0

--- a/mysql-test/suite/pbxt/r/subselect.result
+++ b/mysql-test/suite/pbxt/r/subselect.result
@@ -906,7 +906,7 @@ explain extended SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) F
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t1	index	NULL	PRIMARY	4	NULL	4	100.00	Using index
 2	DEPENDENT SUBQUERY	t2	ref_or_null	a	a	5	func	2	100.00	Using index
-2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer
+2	DEPENDENT SUBQUERY	t3	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t1`.`a` AS `a`,<in_optimizer>(`test`.`t1`.`a`,<exists>(select 1 from `test`.`t2` join `test`.`t3` where ((`test`.`t3`.`a` = `test`.`t2`.`a`) and ((<cache>(`test`.`t1`.`a`) = `test`.`t2`.`a`) or isnull(`test`.`t2`.`a`))) having <is_not_null_test>(`test`.`t2`.`a`))) AS `t1.a in (select t2.a from t2,t3 where t3.a=t2.a)` from `test`.`t1`
 drop table t1,t2,t3;
@@ -1296,7 +1296,7 @@ a
 explain extended select * from t2 where t2.a in (select a from t1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer
+1	PRIMARY	t1	index	PRIMARY	PRIMARY	4	NULL	4	75.00	Using where; Using index; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where (`test`.`t1`.`a` = `test`.`t2`.`a`)
 select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
@@ -1306,7 +1306,7 @@ a
 explain extended select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	PRIMARY	t2	index	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t1`.`b` <> 30))
 select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
@@ -1316,7 +1316,7 @@ 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	PRIMARY	PRIMARY	4	NULL	4	100.00	Using index
-1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer
+1	PRIMARY	t1	ALL	PRIMARY	NULL	NULL	NULL	4	75.00	Using where; Using join buffer (flat, BNL join)
 1	PRIMARY	t3	eq_ref	PRIMARY	PRIMARY	4	test.t1.b	1	100.00	Using index
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a` from `test`.`t1` join `test`.`t3` join `test`.`t2` where ((`test`.`t1`.`a` = `test`.`t2`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`b`))
@@ -3554,7 +3554,7 @@ WHERE t1.t < t2.t  AND t1.i2=1 AND t2.i1=t1.i1
 ORDER BY t1.t DESC LIMIT 1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	1	
-1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index; Using join buffer
+1	PRIMARY	t1	index	NULL	PRIMARY	16	NULL	11	Using where; Using index; Using join buffer (flat, BNL join)
 2	DEPENDENT SUBQUERY	t1	ref	PRIMARY	PRIMARY	8	test.t2.i1,const	1	Using where; Using index; Using filesort
 SELECT * FROM t1,t2
 WHERE t1.t = (SELECT t1.t FROM t1 

--- a/mysql-test/suite/pbxt/r/union.result
+++ b/mysql-test/suite/pbxt/r/union.result
@@ -500,7 +500,7 @@ explain (select * from t1 where a=1 and b=10) union (select straight_join t1.a,t
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
 2	UNION	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index
-2	UNION	t2	index	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index; Using join buffer
+2	UNION	t2	index	PRIMARY	PRIMARY	4	NULL	4	Using where; Using index; Using join buffer (flat, BNL join)
 NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
 explain (select * from t1 where a=1) union (select * from t1 where b=1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

--- a/mysql-test/suite/vcol/r/vcol_misc.result
+++ b/mysql-test/suite/vcol/r/vcol_misc.result
@@ -10,7 +10,7 @@ explain
 select * from t1,t2 where t1.b=t2.c and d <= 100;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
-1	SIMPLE	t2	ref	idx	idx	5	test.t1.b	2	Using where; Using join buffer
+1	SIMPLE	t2	ref	idx	idx	5	test.t1.b	2	Using where; Using join buffer (flat, BKA join)
 select * from t1,t2 where t1.b=t2.c and d <= 100;
 a	b	c	d	v
 4	20	20	100	101

--- a/mysql-test/suite/vcol/r/vcol_select_innodb.result
+++ b/mysql-test/suite/vcol/r/vcol_select_innodb.result
@@ -64,7 +64,7 @@ a	b	c
 explain select * from t1 where b in (select c from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	index	c	c	5	NULL	3	Using index
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 # select_type=PRIMARY, type=range,ref
 select * from t1 where c in (select c from t3 where c between -2 and -1);
 a	b	c

--- a/mysql-test/suite/vcol/r/vcol_select_myisam.result
+++ b/mysql-test/suite/vcol/r/vcol_select_myisam.result
@@ -64,7 +64,7 @@ a	b	c
 explain select * from t1 where b in (select c from t3);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t3	index	c	c	5	NULL	3	Using index
-1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	5	Using where; Using join buffer (flat, BNL join)
 # select_type=PRIMARY, type=range,ref
 select * from t1 where c in (select c from t3 where c between -2 and -1);
 a	b	c

--- a/sql/sql_join_cache.cc
+++ b/sql/sql_join_cache.cc
@@ -2372,6 +2372,54 @@ enum_nested_loop_state JOIN_CACHE::join_null_complements(bool skip_last)
  return rc;
 }
+/*
+  Add a comment on the join algorithm employed by the join cache 
+  SYNOPSIS
+    print_explain_comment()
+      str  string to add the comment on the employed join algorithm to
+  DESCRIPTION
+    This function adds info on the type of the used join buffer (flat or
+    incremental) and on the type of the the employed join algorithm (BNL,
+    BNLH, BKA or BKAH) to the the end of the sring str.
+  RETURN VALUE
+    none
+*/ 
+void JOIN_CACHE::print_explain_comment(String *str)
+{
+  str->append(STRING_WITH_LEN(" ("));
+  const char *buffer_type= prev_cache ? "incremental" : "flat";
+  str->append(buffer_type);
+  str->append(STRING_WITH_LEN(", "));
+  const char *join_alg;
+  switch (get_join_alg()) {
+  case BNL_JOIN_ALG:
+    join_alg= "BNL";
+    break;
+  case BNLH_JOIN_ALG:
+    join_alg= "BNLH";
+    break;
+  case BKA_JOIN_ALG:
+    join_alg= "BKA";
+    break;
+  case BKAH_JOIN_ALG:
+    join_alg= "BKAH";
+    break;
+  default:
+    DBUG_ASSERT(0);
+  }
+  str->append(join_alg);
+  str->append(STRING_WITH_LEN(" join"));
+  str->append(STRING_WITH_LEN(")"));
+ }
 /* 
  Initialize a hashed join cache       

--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -7644,9 +7644,8 @@ uint check_join_cache_usage(JOIN_TAB *tab,
  case JT_ALL:
    if (cache_level == 1)
      prev_cache= 0;
-    if ((options & SELECT_DESCRIBE) ||
+    if ((tab->cache= new JOIN_CACHE_BNL(join, tab, prev_cache)) &&
-        (((tab->cache= new JOIN_CACHE_BNL(join, tab, prev_cache))) &&
+        ((options & SELECT_DESCRIBE) || !tab->cache->init()))
-         !tab->cache->init()))
    {
      *icp_other_tables_ok= FALSE;
      return (2-test(!prev_cache));
@@ -7670,9 +7669,8 @@ uint check_join_cache_usage(JOIN_TAB *tab,
    {
      if (cache_level == 3)
        prev_cache= 0;
-      if ((options & SELECT_DESCRIBE) ||
+      if ((tab->cache= new JOIN_CACHE_BNLH(join, tab, prev_cache)) &&
-	  ((tab->cache= new JOIN_CACHE_BNLH(join, tab, prev_cache)) &&
+          ((options & SELECT_DESCRIBE) || !tab->cache->init()))
-           !tab->cache->init()))
      {
        *icp_other_tables_ok= FALSE;        
        return (4-test(!prev_cache));
@@ -7692,9 +7690,8 @@ uint check_join_cache_usage(JOIN_TAB *tab,
      {
        if (cache_level == 5)
          prev_cache= 0;
-        if ((options & SELECT_DESCRIBE) ||
+        if ((tab->cache= new JOIN_CACHE_BKA(join, tab, flags, prev_cache)) &&
-            ((tab->cache= new JOIN_CACHE_BKA(join, tab, flags, prev_cache)) &&
+            ((options & SELECT_DESCRIBE) || !tab->cache->init()))
-            !tab->cache->init()))
          return (6-test(!prev_cache));
        goto no_join_cache;
      }
@@ -7702,9 +7699,8 @@ uint check_join_cache_usage(JOIN_TAB *tab,
      {
        if (cache_level == 7)
          prev_cache= 0;
-        if ((options & SELECT_DESCRIBE) ||
+        if ((tab->cache= new JOIN_CACHE_BKAH(join, tab, flags, prev_cache)) &&
-            ((tab->cache= new JOIN_CACHE_BKAH(join, tab, flags, prev_cache)) &&
+            ((options & SELECT_DESCRIBE) || !tab->cache->init()))
-            !tab->cache->init()))
 	{
          *idx_cond_fact_out= FALSE;
          return (8-test(!prev_cache));
@@ -18923,8 +18919,11 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
          }
        }
-        if (i > 0 && tab[-1].next_select == sub_select_cache)
+        if (tab->cache)
+	{
          extra.append(STRING_WITH_LEN("; Using join buffer"));
+          tab->cache->print_explain_comment(&extra);
+        }
        /* Skip initial "; "*/
        const char *str= extra.ptr();

--- a/sql/sql_select.h
+++ b/sql/sql_select.h