Backport into MariaDB-5.2 the following:

WL#2474 "Multi Range Read: Change the default MRR implementation to implement new MRR interface"
WL#2475 "Batched range read functions for MyISAM/InnoDb"
        "Index condition pushdown for MyISAM/InnoDB"
- Adjust test results (checked)
- Code cleanup.

mysql-test/r/myisam_mrr.result

@@ -3,9 +3,6 @@ set @read_rnd_buffer_size_save= @@read_rnd_buffer_size;
 set read_rnd_buffer_size=79;
 Warnings:
 Warning	1292	Truncated incorrect read_rnd_buffer_size value: '79'
-select @@read_rnd_buffer_size;
-@@read_rnd_buffer_size
-8228
 create table t1(a int);
 show create table t1;
 Table	Create Table

mysql-test/suite/maria/r/maria.result

@@ -382,20 +382,20 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 explain select * from t1,t2 where t1.b=t2.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	b	NULL	NULL	NULL	2	
-1	SIMPLE	t1	ref	b	b	5	test.t2.b	1	Using where
+1	SIMPLE	t1	ref	b	b	5	test.t2.b	1	
 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	ref	a	a	4	test.t2.a	3	
 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	range	a	a	4	NULL	4	Using where
+1	SIMPLE	t1	range	a	a	4	NULL	4	Using index condition; Using MRR
 explain select * from t1 force index (a) where a=0 or a=2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	range	a	a	4	NULL	4	Using where
+1	SIMPLE	t1	range	a	a	4	NULL	4	Using index condition; Using MRR
 explain select * from t1 where c=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	c,c_2	c	5	const	1	Using where
+1	SIMPLE	t1	ref	c,c_2	c	5	const	1	
 explain select * from t1 use index() where c=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	5	Using where
@@ -1131,7 +1131,7 @@ qq
 *a         *a*a         *
 explain select * from t1 where v='a';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	v,v_2	#	13	const	#	Using where
+1	SIMPLE	t1	ref	v,v_2	#	13	const	#	Using index condition
 select v,count(*) from t1 group by v limit 10;
 v	count(*)
 a
	1
@@ -1307,7 +1307,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	v	v	303	const	#	Using where; Using index
 explain select * from t1 where v='a';
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	v	v	303	const	#	Using where
+1	SIMPLE	t1	ref	v	v	303	const	#	Using index condition
 select v,count(*) from t1 group by v limit 10;
 v	count(*)
 a
	1

mysql-test/suite/parts/r/partition_special_innodb.result

@@ -31,9 +31,9 @@ a	b	c	d
 2000-06-15	jukg	zikhuk	m
 select * from t1 where a<19851231;
 a	b	c	d
-1983-12-31	cdef	srtbvsr	w
-1980-10-14	fgbbd	dtzndtz	w
 1975-01-01	abcde	abcde	m
+1980-10-14	fgbbd	dtzndtz	w
+1983-12-31	cdef	srtbvsr	w
 drop table t1;
 create table t1 (a date not null, b varchar(50) not null, c varchar(50) not null, d enum('m', 'w') not null, e int not null, f decimal (18,2) not null, g bigint not null, h tinyint not null, i char(255), primary key(a,b,c,d,e,f,g,h)) engine='InnoDB' 
 partition by key(a,b,c,d,e,f,g,h) (
@@ -73,9 +73,9 @@ a	b	c	d	e	f	g	h	i
 2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	pib mdotkbm.m
 select * from t1 where a<19851231;
 a	b	c	d	e	f	g	h	i
+1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
 1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
-1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 drop table t1;
 create table t1 (a date not null, b varchar(50) not null, c varchar(50) not null, d enum('m', 'w') not null, e int not null, f decimal (18,2) not null, g bigint not null, h tinyint not null, a1 date not null, b1 varchar(50) not null, c1 varchar(50) not null, d1 enum('m', 'w') not null, e1 int not null, f1 decimal (18,2) not null, g1 bigint not null, h1 tinyint not null, i char(255), primary key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1)) engine='InnoDB' 
 partition by key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1) (
@@ -123,9 +123,9 @@ a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	i
 2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	pib mdotkbm.m
 select * from t1 where a<19851231;
 a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	i
-1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
-1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
 1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
+1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
+1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
 drop table t1;
 create table t1 (a date not null, b varchar(50) not null, c varchar(50) not null, d enum('m', 'w') not null, e int not null, f decimal (18,2) not null, g bigint not null, h tinyint not null, a1 date not null, b1 varchar(50) not null, c1 varchar(50) not null, d1 enum('m', 'w') not null, e1 int not null, f1 decimal (18,2) not null, g1 bigint not null, h1 tinyint not null, a2 date not null, b2 varchar(50) not null, c2 varchar(50) not null, d2 enum('m', 'w') not null, e2 int not null, f2 decimal (18,2) not null, g2 bigint not null, h2 tinyint not null, a3 date not null, b3 varchar(50) not null, c3 varchar(50) not null, d3 enum('m', 'w') not null, e3 int not null, f3 decimal (18,2) not null, g3 bigint not null, h3 tinyint not null, i char(255), primary key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1,a2,b2,c2,d2,e2,f2,g2,h2,a3,b3,c3,d3,e3,f3,g3,h3,a4)) engine='InnoDB' 
 partition by key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1,a2,b2,c2,d2,e2,f2,g2,h2,a3,b3,c3,d3,e3,f3,g3,h3,a4) (
@@ -203,9 +203,9 @@ a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	a2	b2	c2	d2	e2	f2	g2	h2	a3	b3	c3	d3	e3	f
 2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	pib mdotkbm.m
 select * from t1 where a<19851231;
 a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	a2	b2	c2	d2	e2	f2	g2	h2	a3	b3	c3	d3	e3	f3	g3	h3	i
+1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
 1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
-1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 drop table t1;
 # Bug#34604 - Assertion 'inited==RND' failed in handler::ha_rnd_end
 CREATE TABLE t1 (

mysql-test/suite/parts/r/partition_special_myisam.result

@@ -73,9 +73,9 @@ a	b	c	d	e	f	g	h	i
 2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	pib mdotkbm.m
 select * from t1 where a<19851231;
 a	b	c	d	e	f	g	h	i
+1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
 1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
-1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 drop table t1;
 create table t1 (a date not null, b varchar(50) not null, c varchar(50) not null, d enum('m', 'w') not null, e int not null, f decimal (18,2) not null, g bigint not null, h tinyint not null, a1 date not null, b1 varchar(50) not null, c1 varchar(50) not null, d1 enum('m', 'w') not null, e1 int not null, f1 decimal (18,2) not null, g1 bigint not null, h1 tinyint not null, i char(255), primary key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1)) engine='MyISAM' 
 partition by key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1) (
@@ -123,9 +123,9 @@ a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	i
 2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	pib mdotkbm.m
 select * from t1 where a<19851231;
 a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	i
-1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
-1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
 1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
+1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
+1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
 drop table t1;
 create table t1 (a date not null, b varchar(50) not null, c varchar(50) not null, d enum('m', 'w') not null, e int not null, f decimal (18,2) not null, g bigint not null, h tinyint not null, a1 date not null, b1 varchar(50) not null, c1 varchar(50) not null, d1 enum('m', 'w') not null, e1 int not null, f1 decimal (18,2) not null, g1 bigint not null, h1 tinyint not null, a2 date not null, b2 varchar(50) not null, c2 varchar(50) not null, d2 enum('m', 'w') not null, e2 int not null, f2 decimal (18,2) not null, g2 bigint not null, h2 tinyint not null, a3 date not null, b3 varchar(50) not null, c3 varchar(50) not null, d3 enum('m', 'w') not null, e3 int not null, f3 decimal (18,2) not null, g3 bigint not null, h3 tinyint not null, i char(255), primary key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1,a2,b2,c2,d2,e2,f2,g2,h2,a3,b3,c3,d3,e3,f3,g3,h3,a4)) engine='MyISAM' 
 partition by key(a,b,c,d,e,f,g,h,a1,b1,c1,d1,e1,f1,g1,h1,a2,b2,c2,d2,e2,f2,g2,h2,a3,b3,c3,d3,e3,f3,g3,h3,a4) (
@@ -203,7 +203,7 @@ a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	a2	b2	c2	d2	e2	f2	g2	h2	a3	b3	c3	d3	e3	f
 2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	2000-06-15	jukg	zikhuk	m	45675	6465754.13	435242623462	18	pib mdotkbm.m
 select * from t1 where a<19851231;
 a	b	c	d	e	f	g	h	a1	b1	c1	d1	e1	f1	g1	h1	a2	b2	c2	d2	e2	f2	g2	h2	a3	b3	c3	d3	e3	f3	g3	h3	i
+1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	1980-10-14	fgbbd	dtzndtz	w	67856	5463354.67	3567845333	124	d,f söierugsig msireg siug ei5ggth lrutluitgzeöjrtnb.rkjthuekuhzrkuthgjdnffjmbr
 1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	1983-12-31	cdef	srtbvsr	w	45634	13452.56	3452346456	127	liuugbzvdmrlti b itiortudirtfgtibm dfi
-1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	1975-01-01	abcde	abcde	m	1234	123.45	32412341234	113	tbhth nrzh ztfghgfh fzh ftzhj fztjh
 drop table t1;

mysql-test/suite/pbxt/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 temporary
 1	SIMPLE	t2	ref	a	a	4	test.t1.a	1	Using index
-1	SIMPLE	t3	ref	a	a	5	test.t1.b	1	Using where; Using index
+1	SIMPLE	t3	ref	a	a	5	test.t1.b	1	Using index
 SELECT distinct t3.a FROM t3,t2,t1 WHERE t3.a=t1.b AND t1.a=t2.a;
 a
 1
@@ -190,7 +190,7 @@ insert into t3 select * from t4;
 explain select distinct t1.a from t1,t3 where t1.a=t3.a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	4	Using index; Using temporary
-1	SIMPLE	t3	ref	a	a	5	test.t1.a	1	Using where; Using index; Distinct
+1	SIMPLE	t3	ref	a	a	5	test.t1.a	1	Using index; Distinct
 select distinct t1.a from t1,t3 where t1.a=t3.a;
 a
 1

mysql-test/suite/pbxt/r/explain.result

@@ -50,7 +50,7 @@ insert into
 insert into  (0) values (2);
 explain select 0 from  where 0=1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE		ref	0,01	0	5	const	1	Using where; Using index
+1	SIMPLE		ref	0,01	0	5	const	1	Using index
 drop table ;
 set names latin1;
 select 3 into @v1;

mysql-test/suite/pbxt/r/heap.result

@@ -204,7 +204,7 @@ key a (a)
 INSERT INTO t1 VALUES (10), (10), (10);
 EXPLAIN SELECT * FROM t1 WHERE a=10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	a	a	5	const	3	Using where
+1	SIMPLE	t1	ref	a	a	5	const	3	
 SELECT * FROM t1 WHERE a=10;
 a
 10

mysql-test/suite/pbxt/r/join.result

@@ -774,7 +774,7 @@ insert into t3 select * from t2 where a < 800;
 explain select * from t2,t3 where t2.a < 200 and t2.b=t3.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	a,b	a	5	NULL	1	Using where
-1	SIMPLE	t3	ref	b	b	5	test.t2.b	1	Using where
+1	SIMPLE	t3	ref	b	b	5	test.t2.b	1	
 drop table t1, t2, t3;
 create table t1 (a int);
 insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);

mysql-test/suite/pbxt/r/join_nested.result

@@ -74,7 +74,7 @@ WHERE t3.a=1 OR t3.c IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t2` left join (`test`.`t3` join `test`.`t4`) on((`test`.`t4`.`b` = `test`.`t2`.`b`)) where ((`test`.`t3`.`a` = 1) or isnull(`test`.`t3`.`c`))
 SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
@@ -150,7 +150,7 @@ WHERE t3.a>1 OR t3.c IS NULL;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b` from `test`.`t2` left join (`test`.`t3` join `test`.`t4` join `test`.`t5`) on((`test`.`t4`.`b` = `test`.`t2`.`b`)) where ((`test`.`t3`.`a` > 1) or isnull(`test`.`t3`.`c`))
@@ -180,7 +180,7 @@ WHERE (t3.a>1 OR t3.c IS NULL) AND
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b` from `test`.`t2` left join (`test`.`t3` join `test`.`t4` join `test`.`t5`) on((`test`.`t4`.`b` = `test`.`t2`.`b`)) where (((`test`.`t3`.`a` > 1) or isnull(`test`.`t3`.`c`)) and ((`test`.`t5`.`a` < 3) or isnull(`test`.`t5`.`c`)))
@@ -230,7 +230,7 @@ ON t7.b=t8.b AND t6.b < 10;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	100.00	
 1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer
-1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b` from `test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t7`.`b` = `test`.`t8`.`b`) and (`test`.`t6`.`b` < 10))) where 1
 SELECT t6.a,t6.b,t7.a,t7.b,t8.a,t8.b
@@ -546,12 +546,12 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where; Using join buffer
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
-1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 1	SIMPLE	t5	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	
-1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t7	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+1	SIMPLE	t6	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
+1	SIMPLE	t8	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 Warnings:
 Note	1003	select `test`.`t0`.`a` AS `a`,`test`.`t0`.`b` AS `b`,`test`.`t1`.`a` AS `a`,`test`.`t1`.`b` AS `b`,`test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b`,`test`.`t5`.`a` AS `a`,`test`.`t5`.`b` AS `b`,`test`.`t6`.`a` AS `a`,`test`.`t6`.`b` AS `b`,`test`.`t7`.`a` AS `a`,`test`.`t7`.`b` AS `b`,`test`.`t8`.`a` AS `a`,`test`.`t8`.`b` AS `b` from `test`.`t0` join `test`.`t1` left join (`test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t3`.`a` = 1))) join `test`.`t5` left join (`test`.`t6` join `test`.`t7` left join `test`.`t8` on(((`test`.`t8`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` < 10)))) on(((`test`.`t7`.`b` = `test`.`t5`.`b`) and (`test`.`t6`.`b` >= 2)))) on((((`test`.`t3`.`b` = 2) or isnull(`test`.`t3`.`c`)) and ((`test`.`t6`.`b` = 2) or isnull(`test`.`t6`.`c`)) and ((`test`.`t5`.`b` = `test`.`t0`.`b`) or isnull(`test`.`t3`.`c`) or isnull(`test`.`t6`.`c`) or isnull(`test`.`t8`.`c`)) and (`test`.`t1`.`a` <> 2))) where ((`test`.`t1`.`b` = `test`.`t0`.`b`) and (`test`.`t0`.`a` = 1) and ((`test`.`t2`.`a` >= 4) or isnull(`test`.`t2`.`c`)))
 SELECT t0.a,t0.b,t1.a,t1.b,t2.a,t2.b,t3.a,t3.b,t4.a,t4.b,
@@ -837,8 +837,8 @@ WHERE t1.a <= 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using join buffer
-1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
-1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
+1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 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`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t1` join `test`.`t2` left join (`test`.`t3` join `test`.`t4`) on(((`test`.`t4`.`b` = `test`.`t2`.`b`) and (`test`.`t3`.`a` = 1))) where (`test`.`t1`.`a` <= 2)
 CREATE INDEX idx_b ON t2(b);
@@ -851,7 +851,7 @@ ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	
 1	SIMPLE	t4	ALL	NULL	NULL	NULL	NULL	2	100.00	Using join buffer
-1	SIMPLE	t2	ref	idx_b	idx_b	5	test.t3.b	1	100.00	
+1	SIMPLE	t2	ref	idx_b	idx_b	5	test.t3.b	1	100.00	Using where
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	100.00	
 Warnings:
 Note	1003	select `test`.`t2`.`a` AS `a`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`a` AS `a`,`test`.`t3`.`b` AS `b`,`test`.`t4`.`a` AS `a`,`test`.`t4`.`b` AS `b` from `test`.`t3` join `test`.`t4` left join (`test`.`t1` join `test`.`t2`) on(((`test`.`t3`.`a` = 1) and (`test`.`t3`.`b` = `test`.`t2`.`b`) and (`test`.`t2`.`b` = `test`.`t4`.`b`))) where 1
@@ -1054,8 +1054,8 @@ t0.b=t1.b AND
 (t8.b=t9.b OR t8.c IS NULL) AND
 (t9.a=1);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
-1	SIMPLE	t0	ref	idx_a	idx_a	5	const	1	100.00	Using where
-1	SIMPLE	t1	ref	idx_b	idx_b	5	test.t0.b	1	100.00	Using where
+1	SIMPLE	t0	ref	idx_a	idx_a	5	const	1	100.00	
+1	SIMPLE	t1	ref	idx_b	idx_b	5	test.t0.b	1	100.00	
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	100.00	Using where
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 1	SIMPLE	t4	ref	idx_b	idx_b	5	test.t2.b	1	100.00	
@@ -1202,13 +1202,13 @@ test.t3	analyze	status	OK
 EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON c < 3 and b = c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	NULL	a	5	NULL	21	Using index
-1	SIMPLE	t3	index	c	c	5	NULL	6	Using index
+1	SIMPLE	t3	index	c	c	5	NULL	6	Using where; Using index
 1	SIMPLE	t2	ref	b	b	5	test.t3.c	1	Using index
 EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	NULL	a	5	NULL	#	Using index
 1	SIMPLE	t3	index	c	c	5	NULL	#	Using index
-1	SIMPLE	t2	ref	b	b	5	test.t3.c	#	Using index
+1	SIMPLE	t2	ref	b	b	5	test.t3.c	#	Using where; Using index
 SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
 a	b	c
 NULL	0	0
@@ -1279,7 +1279,7 @@ EXPLAIN SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	NULL	a	5	NULL	#	Using index
 1	SIMPLE	t3	index	c	c	5	NULL	#	Using index
-1	SIMPLE	t2	ref	b	b	5	test.t3.c	#	Using index
+1	SIMPLE	t2	ref	b	b	5	test.t3.c	#	Using where; Using index
 SELECT a, b, c FROM t1 LEFT JOIN (t2, t3) ON b < 3 and b = c;
 a	b	c
 NULL	NULL	NULL
@@ -1323,8 +1323,8 @@ c11	c21	c31
 EXPLAIN SELECT * FROM t1 LEFT JOIN (t2 LEFT JOIN t3 ON c21=c31) ON c11=c21;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	
-1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	0	
-1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	0	
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	0	Using where
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	0	Using where
 DROP TABLE t1,t2,t3;
 CREATE TABLE t1 (goods int(12) NOT NULL, price varchar(128) NOT NULL);
 INSERT INTO t1 VALUES (23, 2340), (26, 9900);

mysql-test/suite/pbxt/r/key_cache.result

@@ -122,7 +122,7 @@ i
 explain select count(*) from t1, t2 where t1.p = t2.i;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	2	Using index
-1	SIMPLE	t2	ref	k1	k1	5	test.t1.p	1	Using where; Using index
+1	SIMPLE	t2	ref	k1	k1	5	test.t1.p	1	Using index
 select count(*) from t1, t2 where t1.p = t2.i;
 count(*)
 3

mysql-test/suite/pbxt/r/negation_elimination.result

@@ -79,7 +79,7 @@ a
 19
 explain select * from t1 where not(a != 10);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	a	a	5	const	1	Using where; Using index
+1	SIMPLE	t1	ref	a	a	5	const	1	Using index
 select * from t1 where not(a != 1);
 a
 1

mysql-test/suite/pbxt/r/null.result

@@ -170,7 +170,7 @@ insert into t1 select i*2 from t1;
 insert into t1 values(null);
 explain select * from t1 where i=2 or i is null;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref_or_null	i	i	5	const	#	Using where; Using index
+1	SIMPLE	t1	ref_or_null	i	i	5	const	#	Using index
 select count(*) from t1 where i=2 or i is null;
 count(*)
 10

mysql-test/suite/pbxt/r/null_key.result

@@ -21,10 +21,10 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	range	a,b	a	9	NULL	3	Using where; Using index
 explain select * from t1 where (a is null or a = 7) and b=7;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref_or_null	a,b	a	9	const,const	2	Using where; Using index
+1	SIMPLE	t1	ref_or_null	a,b	a	9	const,const	2	Using index
 explain select * from t1 where (a is null or a = 7) and b=7 order by a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref_or_null	a,b	a	9	const,const	2	Using where; Using index; Using filesort
+1	SIMPLE	t1	ref_or_null	a,b	a	9	const,const	2	Using index; Using filesort
 explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	a,b	a	5	const	3	Using where; Using index
@@ -151,7 +151,7 @@ alter table t1 modify b int null;
 insert into t1 values (7,null), (8,null), (8,7);
 explain select * from t1 where a = 7 and (b=7 or b is null);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref_or_null	a,b	a	10	const,const	2	Using where; Using index
+1	SIMPLE	t1	ref_or_null	a,b	a	10	const,const	2	Using index
 select * from t1 where a = 7 and (b=7 or b is null);
 a	b
 7	7
@@ -166,7 +166,7 @@ a	b
 NULL	7
 explain select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref_or_null	a	a	5	const	5	Using where; Using index
+1	SIMPLE	t1	ref_or_null	a	a	5	const	5	Using index
 select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
 a	b
 7	NULL
@@ -192,7 +192,7 @@ a	a	b
 explain select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
 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	ref_or_null	a	a	10	test.t2.a,const	4	Using where; Using index
+1	SIMPLE	t1	ref_or_null	a	a	10	test.t2.a,const	4	Using index
 select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
 a	a	b
 7	7	7
@@ -202,7 +202,7 @@ a	a	b
 explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
 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	ref_or_null	a	a	10	test.t2.a,const	4	Using where; Using index
+1	SIMPLE	t1	ref_or_null	a	a	10	test.t2.a,const	4	Using index
 select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
 a	a	b
 7	7	7
@@ -226,7 +226,7 @@ delete from t1 where a=8;
 explain select * from t2,t1 where t1.a=t2.a or t1.a is null;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	4	
-1	SIMPLE	t1	ref_or_null	a	a	5	test.t2.a	4	Using where; Using index
+1	SIMPLE	t1	ref_or_null	a	a	5	test.t2.a	4	Using index
 explain select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	4	
@@ -258,7 +258,7 @@ INSERT INTO t1 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4
 INSERT INTO t2 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
 explain select id from t1 where uniq_id is null;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	SIMPLE	t1	ref	idx1	idx1	5	const	5	Using where
+1	SIMPLE	t1	ref	idx1	idx1	5	const	5	Using index condition
 explain select id from t1 where uniq_id =1;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	const	idx1	idx1	5	const	1	

mysql-test/t/myisam_mrr.test

@@ -8,7 +8,6 @@ drop table if exists t1, t2, t3;
 
 set @read_rnd_buffer_size_save= @@read_rnd_buffer_size;
 set read_rnd_buffer_size=79;
-select @@read_rnd_buffer_size;
 
 -- source include/mrr_tests.inc
 

sql/ds_mrr.cc

@@ -950,8 +950,15 @@ void push_index_cond(JOIN_TAB *tab, uint keyno, bool other_tbls_ok)
     ((tab->table->file->index_flags(keyno, 0, 1) &
       HA_DO_INDEX_COND_PUSHDOWN) &&
      tab->join->thd->variables.engine_condition_pushdown);
-  // psergey:
-  //
+
+  /*
+    Do not try index condition pushdown on indexes which have partially-covered
+    columns. Unpacking from a column prefix into index tuple is not a supported 
+    operation in some engines, see e.g. MySQL BUG#42991.
+    TODO: a better solution would be not to consider partially-covered columns
+    as parts of the index and still produce/check index condition for
+    fully-covered index columns.
+  */
   KEY *key_info= tab->table->key_info + keyno;
   for (uint kp= 0; kp < key_info->key_parts; kp++)
   {
@@ -961,7 +968,7 @@ void push_index_cond(JOIN_TAB *tab, uint keyno, bool other_tbls_ok)
       break;
     }
   }
-  // :psergey
+
   /*
     When WL#5116 is done this DBUG statement must be removed. It's just a
     temporary hack to allow us to discriminate whether a test failure relates
@@ -984,7 +991,8 @@ void push_index_cond(JOIN_TAB *tab, uint keyno, bool other_tbls_ok)
       Item *idx_remainder_cond= 0;
       tab->pre_idx_push_select_cond= tab->select_cond;
 #if 0
-      // The following is only needed for BKA:
+      /* 
+        psergey: enable the below when we backport BKA: */
       /*
         For BKA cache we store condition to special BKA cache field
         because evaluation of the condition requires additional operations

sql/ds_mrr.h

-
+/*
+  This file contains declarations for 
+   - Disk-Sweep MultiRangeRead (DS-MRR) implementation
+   - Index Condition Pushdown helper functions
+*/
 
 /**
   A Disk-Sweep MRR interface implementation
@@ -65,4 +69,5 @@ class DsMrr_impl
                                uint *buffer_size, COST_VECT *cost);
 };
 
+void push_index_cond(JOIN_TAB *tab, uint keyno, bool other_tbls_ok);
 

sql/ha_ndbcluster.cc

@@ -8702,6 +8702,8 @@ ha_ndbcluster::null_value_index_search(KEY_MULTI_RANGE *ranges,
   DBUG_RETURN(FALSE);
 }
 
+#if 0 
+/* MRR/NDB is disabled, for details see method declarations in ha_ndbcluster.h */
 int
 ha_ndbcluster::read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
                                       KEY_MULTI_RANGE *ranges, 
@@ -9074,6 +9076,7 @@ ha_ndbcluster::read_multi_range_next(KEY_MULTI_RANGE ** multi_range_found_p)
   m_multi_range_result_ptr += reclength;
   DBUG_RETURN(0);
 }
+#endif 
 
 int
 ha_ndbcluster::setup_recattr(const NdbRecAttr* curr)

sql/ha_ndbcluster.h

@@ -259,10 +259,20 @@ class ha_ndbcluster: public handler
   /**
    * Multi range stuff
    */
+#if 0 
+  /*
+    MRR/NDB is disabled in MariaDB. This is because in MariaDB, we've
+    backported
+     - the latest version of MRR interface (BKA needs this)
+     - the latest version of DS-MRR implementation
+    but didn't backport the latest version MRR/NDB implementation.
+
+  */
   int read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
                              KEY_MULTI_RANGE*ranges, uint range_count,
                              bool sorted, HANDLER_BUFFER *buffer);
   int read_multi_range_next(KEY_MULTI_RANGE **found_range_p);
+#endif  
   bool null_value_index_search(KEY_MULTI_RANGE *ranges,
 			       KEY_MULTI_RANGE *end_range,
 			       HANDLER_BUFFER *buffer);

sql/handler.cc

@@ -4193,136 +4193,6 @@ double handler::index_only_read_time(uint keynr, double records)
   return read_time;
 }
 
-#if 0 
-// psergey-mrr
-
-/**
-  Read the first row of a multi-range set.
-
-  @param found_range_p       Returns a pointer to the element in 'ranges' that
-                             corresponds to the returned row.
-  @param ranges              An array of KEY_MULTI_RANGE range descriptions.
-  @param range_count         Number of ranges in 'ranges'.
-  @param sorted	      If result should be sorted per key.
-  @param buffer              A HANDLER_BUFFER for internal handler usage.
-
-  @note
-    - Record is read into table->record[0].
-    - *found_range_p returns a valid value only if read_multi_range_first()
-    returns 0.
-    - Sorting is done within each range. If you want an overall sort, enter
-    'ranges' with sorted ranges.
-
-  @retval
-    0			OK, found a row
-  @retval
-    HA_ERR_END_OF_FILE	No rows in range
-  @retval
-    \#			Error code
-*/
-int handler::read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
-                                    KEY_MULTI_RANGE *ranges, uint range_count,
-                                    bool sorted, HANDLER_BUFFER *buffer)
-{
-  int result= HA_ERR_END_OF_FILE;
-  DBUG_ENTER("handler::read_multi_range_first");
-  multi_range_sorted= sorted;
-  multi_range_buffer= buffer;
-
-  table->mark_columns_used_by_index_no_reset(active_index, table->read_set);
-  table->column_bitmaps_set(table->read_set, table->write_set);
-
-  for (multi_range_curr= ranges, multi_range_end= ranges + range_count;
-       multi_range_curr < multi_range_end;
-       multi_range_curr++)
-  {
-    result= read_range_first(multi_range_curr->start_key.keypart_map ?
-                             &multi_range_curr->start_key : 0,
-                             multi_range_curr->end_key.keypart_map ?
-                             &multi_range_curr->end_key : 0,
-                             test(multi_range_curr->range_flag & EQ_RANGE),
-                             multi_range_sorted);
-    if (result != HA_ERR_END_OF_FILE)
-      break;
-  }
-
-  *found_range_p= multi_range_curr;
-  DBUG_PRINT("exit",("result %d", result));
-  DBUG_RETURN(result);
-}
-
-
-/**
-  Read the next row of a multi-range set.
-
-  @param found_range_p       Returns a pointer to the element in 'ranges' that
-                             corresponds to the returned row.
-
-  @note
-    - Record is read into table->record[0].
-    - *found_range_p returns a valid value only if read_multi_range_next()
-    returns 0.
-
-  @retval
-    0			OK, found a row
-  @retval
-    HA_ERR_END_OF_FILE	No (more) rows in range
-  @retval
-    \#			Error code
-*/
-int handler::read_multi_range_next(KEY_MULTI_RANGE **found_range_p)
-{
-  int result;
-  DBUG_ENTER("handler::read_multi_range_next");
-
-  /* We should not be called after the last call returned EOF. */
-  DBUG_ASSERT(multi_range_curr < multi_range_end);
-
-  do
-  {
-    /* Save a call if there can be only one row in range. */
-    if (multi_range_curr->range_flag != (UNIQUE_RANGE | EQ_RANGE))
-    {
-      result= read_range_next();
-
-      /* On success or non-EOF errors jump to the end. */
-      if (result != HA_ERR_END_OF_FILE)
-        break;
-    }
-    else
-    {
-      if (was_semi_consistent_read())
-        goto scan_it_again;
-      /*
-        We need to set this for the last range only, but checking this
-        condition is more expensive than just setting the result code.
-      */
-      result= HA_ERR_END_OF_FILE;
-    }
-
-    multi_range_curr++;
-scan_it_again:
-    /* Try the next range(s) until one matches a record. */
-    for (; multi_range_curr < multi_range_end; multi_range_curr++)
-    {
-      result= read_range_first(multi_range_curr->start_key.keypart_map ?
-                               &multi_range_curr->start_key : 0,
-                               multi_range_curr->end_key.keypart_map ?
-                               &multi_range_curr->end_key : 0,
-                               test(multi_range_curr->range_flag & EQ_RANGE),
-                               multi_range_sorted);
-      if (result != HA_ERR_END_OF_FILE)
-        break;
-    }
-  }
-  while ((result == HA_ERR_END_OF_FILE) &&
-         (multi_range_curr < multi_range_end));
-
-  *found_range_p= multi_range_curr;
-  DBUG_PRINT("exit",("handler::read_multi_range_next: result %d", result));
-  DBUG_RETURN(result);
-}
-#endif
 
 /**
   Read first row between two ranges.

sql/handler.h

@@ -1290,15 +1290,6 @@ class handler :public Sql_alloc
 
   ha_statistics stats;
 
-  /** The following are for read_multi_range */
-//////psergey: was: 
-#if 0
-  bool multi_range_sorted;
-  KEY_MULTI_RANGE *multi_range_curr;
-  KEY_MULTI_RANGE *multi_range_end;
-  HANDLER_BUFFER *multi_range_buffer;
-#endif
-//////psergey
   /** MultiRangeRead-related members: */
   range_seq_t mrr_iter;    /* Interator to traverse the range sequence */
   RANGE_SEQ_IF mrr_funcs;  /* Range sequence traversal functions */
@@ -1311,7 +1302,6 @@ class handler :public Sql_alloc
   bool mrr_have_range;
   /** Current range (the one we're now returning rows from) */
   KEY_MULTI_RANGE mrr_cur_range;
-//////psergey
 
   /** The following are for read_range() */
   key_range save_end_range, *end_range;
@@ -1744,13 +1734,6 @@ class handler :public Sql_alloc
       update_index_statistics();
     return error;
   }
-#if 0
-  virtual int read_multi_range_first(KEY_MULTI_RANGE **found_range_p,
-                                     KEY_MULTI_RANGE *ranges, uint range_count,
-                                     bool sorted, HANDLER_BUFFER *buffer);
-  virtual int read_multi_range_next(KEY_MULTI_RANGE **found_range_p);
-#endif 
-  //psergey-mrr: 
   virtual ha_rows multi_range_read_info_const(uint keyno, RANGE_SEQ_IF *seq,
                                               void *seq_init_param, 
                                               uint n_ranges, uint *bufsz,
@@ -1761,7 +1744,6 @@ class handler :public Sql_alloc
                                     uint n_ranges, uint mode,
                                     HANDLER_BUFFER *buf);
   virtual int multi_range_read_next(char **range_info);
-  //psergey-mrr: ends
   virtual int read_range_first(const key_range *start_key,
                                const key_range *end_key,
                                bool eq_range, bool sorted);

sql/sql_select.cc

@@ -16734,11 +16734,12 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
         if (keyno != MAX_KEY && keyno == table->file->pushed_idx_cond_keyno &&
             table->file->pushed_idx_cond)
           extra.append(STRING_WITH_LEN("; Using index condition"));
-        /**
-        psergey-mrr:
+        /*
+        psergey: enable the below when we backport BKA:
+
         else if (tab->cache_idx_cond)
           extra.append(STRING_WITH_LEN("; Using index condition(BKA)"));
-        **/
+        */
         if (quick_type == QUICK_SELECT_I::QS_TYPE_ROR_UNION || 
             quick_type == QUICK_SELECT_I::QS_TYPE_ROR_INTERSECT ||
             quick_type == QUICK_SELECT_I::QS_TYPE_INDEX_MERGE)

sql/sql_select.h

@@ -780,7 +780,4 @@ inline bool optimizer_flag(THD *thd, uint flag)
 
 void eliminate_tables(JOIN *join);
 
-/// psergey-mrr:
-void push_index_cond(JOIN_TAB *tab, uint keyno, bool other_tbls_ok);
-