drop table if exists t0,t1,t2,t3;
#
# MDEV-6434: Wrong result (extra rows) with ORDER BY, multiple-column index, InnoDB
#
CREATE TABLE t1 (a INT, b INT, c INT, d TEXT, KEY idx(a,b,c)) ENGINE=InnoDB;
INSERT INTO t1 (a,c) VALUES
(8, 9),(8, 10),(13, 15),(16, 17),(16, 18),(16, 19),(20, 21),
(20, 22),(20, 24),(20, 25),(20, 26),(20, 27),(20, 28);
SELECT  * FROM t1 WHERE a = 8 AND (b = 1 OR b IS NULL) ORDER BY c;
a	b	c	d
8	NULL	9	NULL
8	NULL	10	NULL
DROP TABLE t1;
#
# MDEV-9457: Poor query plan chosen for ORDER BY query by a recent 10.1
#
create table t0 (a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (
pk int primary key,
key1 int,
key2 int,
col1 char(255),
key(key1),
key(key2)
) engine=innodb;
set @a=-1;
insert into t1 
select 
@a:=@a+1, 
@a, 
@a, 
repeat('abcd', 63) 
from t0 A, t0 B, t0 C, t0 D;
# The following must NOT use 'index' on PK. 
# It should use index_merge(key1,key2) + filesort
explain 
select * 
from t1
where key1<3 or key2<3
order by pk;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index_merge	key1,key2	key1,key2	5,5	NULL	#	Using sort_union(key1,key2); Using where; Using filesort
explain 
select * 
from t1
where key1<3 or key2<3;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index_merge	key1,key2	key1,key2	5,5	NULL	#	Using sort_union(key1,key2); Using where
drop table t0, t1;
#
# MDEV-18094: Query with order by limit picking index scan over filesort
#
create table t0 (a int);
INSERT INTO t0 VALUES (0),(0),(0),(0),(2),(0),(0),(1),(1),(0);
CREATE TABLE t1 (
a int(11),
b int(11),
c int(11),
KEY a_c (a,c),
KEY a_b (a,b)
) ENGINE=InnoDB;
insert into t1 select A.a , B.a, C.a from t0 A, t0 B, t0 C;
# should use ref access
explain select a,b,c from t1 where a=1 and c=2 order by b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	a_c,a_b	a_c	10	const,const	20	Using where; Using filesort
# both should use range access
explain select a,b,c from t1 where a=1 and c=2 order by b limit 1000;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	a_c,a_b	a_b	5	NULL	200	Using where
explain select a,b,c from t1 where a=1 and c=2 order by b limit 2000;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	a_c,a_b	a_b	5	NULL	200	Using where
drop table t1,t0;