~drizzle-trunk/drizzle/development : contents of tests/r/group_min

~drizzle-trunk/drizzle/development : (revision 1929.1.7)
drop table if exists t1;
create TEMPORARY table t1 (
a1 char(64), a2 char(64), b char(16), c char(16) not null, d char(16), dummy char(64) default ' '
) ENGINE=MYISAM;
insert into t1 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4'),
('d','a','a','a411','xy1'),('d','a','a','b411','xy2'),('d','a','a','c411','xy3'),('d','a','a','d411','xy4'),
('d','a','b','e412','xy1'),('d','a','b','f412','xy2'),('d','a','b','g412','xy3'),('d','a','b','h412','xy4'),
('d','b','a','i421','xy1'),('d','b','a','j421','xy2'),('d','b','a','k421','xy3'),('d','b','a','l421','xy4'),
('d','b','b','m422','xy1'),('d','b','b','n422','xy2'),('d','b','b','o422','xy3'),('d','b','b','p422','xy4'),
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4'),
('d','a','a','a411','xy1'),('d','a','a','b411','xy2'),('d','a','a','c411','xy3'),('d','a','a','d411','xy4'),
('d','a','b','e412','xy1'),('d','a','b','f412','xy2'),('d','a','b','g412','xy3'),('d','a','b','h412','xy4'),
('d','b','a','i421','xy1'),('d','b','a','j421','xy2'),('d','b','a','k421','xy3'),('d','b','a','l421','xy4'),
('d','b','b','m422','xy1'),('d','b','b','n422','xy2'),('d','b','b','o422','xy3'),('d','b','b','p422','xy4');
create index idx_t1_0 on t1 (a1);
create index idx_t1_1 on t1 (a1,a2,b,c);
create index idx_t1_2 on t1 (a1,a2,b);
analyze table t1;
Table	Op	Msg_type	Msg_text
test.t1	analyze	note	The storage engine for the table doesn't support analyze
drop table if exists t2;
create TEMPORARY table t2 (
a1 char(64), a2 char(64) not null, b char(16), c char(16), d char(16), dummy char(64) default ' '
) ENGINE=MYISAM;
insert into t2 select * from t1;
insert into t2 (a1, a2, b, c, d) values
('a','a',NULL,'a777','xyz'),('a','a',NULL,'a888','xyz'),('a','a',NULL,'a999','xyz'),
('a','a','a',NULL,'xyz'),
('a','a','b',NULL,'xyz'),
('a','b','a',NULL,'xyz'),
('c','a',NULL,'c777','xyz'),('c','a',NULL,'c888','xyz'),('c','a',NULL,'c999','xyz'),
('d','b','b',NULL,'xyz'),
('e','a','a',NULL,'xyz'),('e','a','a',NULL,'xyz'),('e','a','a',NULL,'xyz'),('e','a','a',NULL,'xyz'),
('e','a','b',NULL,'xyz'),('e','a','b',NULL,'xyz'),('e','a','b',NULL,'xyz'),('e','a','b',NULL,'xyz'),
('a','a',NULL,'a777','xyz'),('a','a',NULL,'a888','xyz'),('a','a',NULL,'a999','xyz'),
('a','a','a',NULL,'xyz'),
('a','a','b',NULL,'xyz'),
('a','b','a',NULL,'xyz'),
('c','a',NULL,'c777','xyz'),('c','a',NULL,'c888','xyz'),('c','a',NULL,'c999','xyz'),
('d','b','b',NULL,'xyz'),
('e','a','a',NULL,'xyz'),('e','a','a',NULL,'xyz'),('e','a','a',NULL,'xyz'),('e','a','a',NULL,'xyz'),
('e','a','b',NULL,'xyz'),('e','a','b',NULL,'xyz'),('e','a','b',NULL,'xyz'),('e','a','b',NULL,'xyz');
create index idx_t2_0 on t2 (a1);
create index idx_t2_1 on t2 (a1,a2,b,c);
create index idx_t2_2 on t2 (a1,a2,b);
analyze table t2;
Table	Op	Msg_type	Msg_text
test.t2	analyze	note	The storage engine for the table doesn't support analyze
drop table if exists t3;
create TEMPORARY table t3 (
a1 char(1), a2 char(1), b char(1), c char(4) not null, d char(3), dummy char(1) default ' '
) ENGINE=MYISAM;
insert into t3 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4');
insert into t3 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4');
insert into t3 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4');
insert into t3 (a1, a2, b, c, d) values
('a','a','a','a111','xy1'),('a','a','a','b111','xy2'),('a','a','a','c111','xy3'),('a','a','a','d111','xy4'),
('a','a','b','e112','xy1'),('a','a','b','f112','xy2'),('a','a','b','g112','xy3'),('a','a','b','h112','xy4'),
('a','b','a','i121','xy1'),('a','b','a','j121','xy2'),('a','b','a','k121','xy3'),('a','b','a','l121','xy4'),
('a','b','b','m122','xy1'),('a','b','b','n122','xy2'),('a','b','b','o122','xy3'),('a','b','b','p122','xy4'),
('b','a','a','a211','xy1'),('b','a','a','b211','xy2'),('b','a','a','c211','xy3'),('b','a','a','d211','xy4'),
('b','a','b','e212','xy1'),('b','a','b','f212','xy2'),('b','a','b','g212','xy3'),('b','a','b','h212','xy4'),
('b','b','a','i221','xy1'),('b','b','a','j221','xy2'),('b','b','a','k221','xy3'),('b','b','a','l221','xy4'),
('b','b','b','m222','xy1'),('b','b','b','n222','xy2'),('b','b','b','o222','xy3'),('b','b','b','p222','xy4'),
('c','a','a','a311','xy1'),('c','a','a','b311','xy2'),('c','a','a','c311','xy3'),('c','a','a','d311','xy4'),
('c','a','b','e312','xy1'),('c','a','b','f312','xy2'),('c','a','b','g312','xy3'),('c','a','b','h312','xy4'),
('c','b','a','i321','xy1'),('c','b','a','j321','xy2'),('c','b','a','k321','xy3'),('c','b','a','l321','xy4'),
('c','b','b','m322','xy1'),('c','b','b','n322','xy2'),('c','b','b','o322','xy3'),('c','b','b','p322','xy4');
create index idx_t3_0 on t3 (a1);
create index idx_t3_1 on t3 (a1,a2,b,c);
create index idx_t3_2 on t3 (a1,a2,b);
analyze table t3;
Table	Op	Msg_type	Msg_text
test.t3	analyze	note	The storage engine for the table doesn't support analyze
explain select a1, min(a2) from t1 group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	518	NULL	5	Using index for group-by
explain select a1, max(a2) from t1 group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	259	NULL	5	Using index for group-by
explain select a1, min(a2), max(a2) from t1 group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	518	NULL	5	Using index for group-by
explain select a1, a2, b, min(c), max(c) from t1 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
explain select a1,a2,b,max(c),min(c) from t1 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
explain select a1,a2,b,max(c),min(c) from t2 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	#	NULL	#	Using index
explain select min(a2), a1, max(a2), min(a2), a1 from t1 group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	518	NULL	5	Using index for group-by
explain select a1, b, min(c), a1, max(c), b, a2, max(c), max(c) from t1 group by a1, a2, b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
explain select min(a2) from t1 group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	518	NULL	5	Using index for group-by
explain select a2, min(c), max(c) from t1 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
select a1, min(a2) from t1 group by a1;
a1	min(a2)
a	a
b	a
c	a
d	a
select a1, max(a2) from t1 group by a1;
a1	max(a2)
a	b
b	b
c	b
d	b
select a1, min(a2), max(a2) from t1 group by a1;
a1	min(a2)	max(a2)
a	a	b
b	a	b
c	a	b
d	a	b
select a1, a2, b, min(c), max(c) from t1 group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,max(c),min(c) from t1 group by a1,a2,b;
a1	a2	b	max(c)	min(c)
a	a	a	d111	a111
a	a	b	h112	e112
a	b	a	l121	i121
a	b	b	p122	m122
b	a	a	d211	a211
b	a	b	h212	e212
b	b	a	l221	i221
b	b	b	p222	m222
c	a	a	d311	a311
c	a	b	h312	e312
c	b	a	l321	i321
c	b	b	p322	m322
d	a	a	d411	a411
d	a	b	h412	e412
d	b	a	l421	i421
d	b	b	p422	m422
select a1,a2,b,max(c),min(c) from t2 group by a1,a2,b;
a1	a2	b	max(c)	min(c)
a	a	NULL	a999	a777
a	a	a	d111	a111
a	a	b	h112	e112
a	b	a	l121	i121
a	b	b	p122	m122
b	a	a	d211	a211
b	a	b	h212	e212
b	b	a	l221	i221
b	b	b	p222	m222
c	a	NULL	c999	c777
c	a	a	d311	a311
c	a	b	h312	e312
c	b	a	l321	i321
c	b	b	p322	m322
d	a	a	d411	a411
d	a	b	h412	e412
d	b	a	l421	i421
d	b	b	p422	m422
e	a	a	NULL	NULL
e	a	b	NULL	NULL
select min(a2), a1, max(a2), min(a2), a1 from t1 group by a1;
min(a2)	a1	max(a2)	min(a2)	a1
a	a	b	a	a
a	b	b	a	b
a	c	b	a	c
a	d	b	a	d
select a1, b, min(c), a1, max(c), b, a2, max(c), max(c) from t1 group by a1, a2, b;
a1	b	min(c)	a1	max(c)	b	a2	max(c)	max(c)
a	a	a111	a	d111	a	a	d111	d111
a	b	e112	a	h112	b	a	h112	h112
a	a	i121	a	l121	a	b	l121	l121
a	b	m122	a	p122	b	b	p122	p122
b	a	a211	b	d211	a	a	d211	d211
b	b	e212	b	h212	b	a	h212	h212
b	a	i221	b	l221	a	b	l221	l221
b	b	m222	b	p222	b	b	p222	p222
c	a	a311	c	d311	a	a	d311	d311
c	b	e312	c	h312	b	a	h312	h312
c	a	i321	c	l321	a	b	l321	l321
c	b	m322	c	p322	b	b	p322	p322
d	a	a411	d	d411	a	a	d411	d411
d	b	e412	d	h412	b	a	h412	h412
d	a	i421	d	l421	a	b	l421	l421
d	b	m422	d	p422	b	b	p422	p422
select min(a2) from t1 group by a1;
min(a2)
a
a
a
a
select a2, min(c), max(c) from t1 group by a1,a2,b;
a2	min(c)	max(c)
a	a111	d111
a	e112	h112
b	i121	l121
b	m122	p122
a	a211	d211
a	e212	h212
b	i221	l221
b	m222	p222
a	a311	d311
a	e312	h312
b	i321	l321
b	m322	p322
a	a411	d411
a	e412	h412
b	i421	l421
b	m422	p422
explain select a1,a2,b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where a1 >= 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1, max(c)            from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where a1 >= 'c' or a2 < 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	8	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	8	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	8	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	8	Using where; Using index for group-by
explain select a1,min(c),max(c)      from t1 where a1 >= 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,  max(c)           from t1 where a1 in ('a','b','d') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t2 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where a1 >= 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t2 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select a1, max(c)            from t2 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where a1 >= 'c' or a2 < 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,       max(c) from t2 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t2 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,min(c),max(c)      from t2 where a1 >= 'b' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,  max(c)           from t2 where a1 in ('a','b','d') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
select a1,a2,b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
select a1,a2,b,min(c),max(c) from t1 where a1 >= 'b' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1, max(c)            from t1 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
a1	max(c)
a	d111
a	h112
a	l121
a	p122
c	d311
c	h312
c	l321
c	p322
d	d411
d	h412
d	l421
d	p422
select a1,a2,b,min(c),max(c) from t1 where a1 >= 'c' or a2 < 'b' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	a111	d111
a	a	b	e112	h112
b	a	a	a211	d211
b	a	b	e212	h212
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
a1	a2	b	max(c)
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t1 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
a1	a2	b	max(c)
a	b	a	l121
a	b	b	p122
b	b	a	l221
b	b	b	p222
c	b	a	l321
c	b	b	p322
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	b	a	i121	l121
a	b	b	m122	p122
b	b	a	i221	l221
b	b	b	m222	p222
c	b	a	i321	l321
c	b	b	m322	p322
d	b	a	i421	l421
d	b	b	m422	p422
select a1,min(c),max(c)      from t1 where a1 >= 'b' group by a1,a2,b;
a1	min(c)	max(c)
b	a211	d211
b	e212	h212
b	i221	l221
b	m222	p222
c	a311	d311
c	e312	h312
c	i321	l321
c	m322	p322
d	a411	d411
d	e412	h412
d	i421	l421
d	m422	p422
select a1,  max(c)           from t1 where a1 in ('a','b','d') group by a1,a2,b;
a1	max(c)
a	d111
a	h112
a	l121
a	p122
b	d211
b	h212
b	l221
b	p222
d	d411
d	h412
d	l421
d	p422
select a1,a2,b,       max(c) from t2 where a1 < 'd' group by a1,a2,b;
a1	a2	b	max(c)
a	a	NULL	a999
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	NULL	c999
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
select a1,a2,b,min(c),max(c) from t2 where a1 < 'd' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	NULL	c777	c999
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
select a1,a2,b,min(c),max(c) from t2 where a1 >= 'b' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	NULL	c777	c999
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
e	a	a	NULL	NULL
e	a	b	NULL	NULL
select a1,a2,b,       max(c) from t2 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
a1	a2	b	max(c)
a	a	NULL	a999
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
c	a	NULL	c999
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
e	a	a	NULL
e	a	b	NULL
select a1, max(c)            from t2 where a1 >= 'c' or a1 < 'b' group by a1,a2,b;
a1	max(c)
a	a999
a	d111
a	h112
a	l121
a	p122
c	c999
c	d311
c	h312
c	l321
c	p322
d	d411
d	h412
d	l421
d	p422
e	NULL
e	NULL
select a1,a2,b,min(c),max(c) from t2 where a1 >= 'c' or a2 < 'b' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
a	a	a	a111	d111
a	a	b	e112	h112
b	a	a	a211	d211
b	a	b	e212	h212
c	a	NULL	c777	c999
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
e	a	a	NULL	NULL
e	a	b	NULL	NULL
select a1,a2,b,       max(c) from t2 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
a1	a2	b	max(c)
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t2 where a1 = 'z' or a1 = 'b' or a1 = 'd' group by a1,a2,b;
a1	a2	b	min(c)	max(c)
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t2 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
a1	a2	b	max(c)
a	b	a	l121
a	b	b	p122
b	b	a	l221
b	b	b	p222
c	b	a	l321
c	b	b	p322
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t2 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	b	a	i121	l121
a	b	b	m122	p122
b	b	a	i221	l221
b	b	b	m222	p222
c	b	a	i321	l321
c	b	b	m322	p322
d	b	a	i421	l421
d	b	b	m422	p422
select a1,min(c),max(c)      from t2 where a1 >= 'b' group by a1,a2,b;
a1	min(c)	max(c)
b	a211	d211
b	e212	h212
b	i221	l221
b	m222	p222
c	c777	c999
c	a311	d311
c	e312	h312
c	i321	l321
c	m322	p322
d	a411	d411
d	e412	h412
d	i421	l421
d	m422	p422
e	NULL	NULL
e	NULL	NULL
select a1,  max(c)           from t2 where a1 in ('a','b','d') group by a1,a2,b;
a1	max(c)
a	a999
a	d111
a	h112
a	l121
a	p122
b	d211
b	h212
b	l221
b	p222
d	d411
d	h412
d	l421
d	p422
explain select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	5	Using where; Using index for group-by
explain select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	5	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (b = 'b') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	9	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (b = 'b') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	9	Using where; Using index for group-by
explain select a1,a2, max(c)         from t1 where (b = 'b') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	9	Using where; Using index for group-by
explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	5	Using where; Using index for group-by
explain select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	5	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t2 where (b = 'b') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	584	NULL	10	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where (b = 'b') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	10	Using where; Using index for group-by
explain select a1,a2, max(c)         from t2 where (b = 'b') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	584	NULL	10	Using where; Using index for group-by
explain select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	range	NULL	idx_t3_1	21	NULL	4	Using where; Using index for group-by
explain select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t3	range	NULL	idx_t3_1	21	NULL	4	Using where; Using index for group-by
select a1,a2,b,max(c),min(c) from t1 where (a2 = 'a') and (b = 'b') group by a1;
a1	a2	b	max(c)	min(c)
a	a	b	h112	e112
b	a	b	h212	e212
c	a	b	h312	e312
d	a	b	h412	e412
select a1,max(c),min(c)      from t1 where (a2 = 'a') and (b = 'b') group by a1;
a1	max(c)	min(c)
a	h112	e112
b	h212	e212
c	h312	e312
d	h412	e412
select a1,a2,b,       max(c) from t1 where (b = 'b') group by a1,a2;
a1	a2	b	max(c)
a	a	b	h112
a	b	b	p122
b	a	b	h212
b	b	b	p222
c	a	b	h312
c	b	b	p322
d	a	b	h412
d	b	b	p422
select a1,a2,b,min(c),max(c) from t1 where (b = 'b') group by a1,a2;
a1	a2	b	min(c)	max(c)
a	a	b	e112	h112
a	b	b	m122	p122
b	a	b	e212	h212
b	b	b	m222	p222
c	a	b	e312	h312
c	b	b	m322	p322
d	a	b	e412	h412
d	b	b	m422	p422
select a1,a2, max(c)         from t1 where (b = 'b') group by a1,a2;
a1	a2	max(c)
a	a	h112
a	b	p122
b	a	h212
b	b	p222
c	a	h312
c	b	p322
d	a	h412
d	b	p422
select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') group by a1;
a1	a2	b	max(c)	min(c)
a	a	b	h112	e112
b	a	b	h212	e212
c	a	b	h312	e312
d	a	b	h412	e412
e	a	b	NULL	NULL
select a1,max(c),min(c)      from t2 where (a2 = 'a') and (b = 'b') group by a1;
a1	max(c)	min(c)
a	h112	e112
b	h212	e212
c	h312	e312
d	h412	e412
e	NULL	NULL
select a1,a2,b,       max(c) from t2 where (b = 'b') group by a1,a2;
a1	a2	b	max(c)
a	a	b	h112
a	b	b	p122
b	a	b	h212
b	b	b	p222
c	a	b	h312
c	b	b	p322
d	a	b	h412
d	b	b	p422
e	a	b	NULL
select a1,a2,b,min(c),max(c) from t2 where (b = 'b') group by a1,a2;
a1	a2	b	min(c)	max(c)
a	a	b	e112	h112
a	b	b	m122	p122
b	a	b	e212	h212
b	b	b	m222	p222
c	a	b	e312	h312
c	b	b	m322	p322
d	a	b	e412	h412
d	b	b	m422	p422
e	a	b	NULL	NULL
select a1,a2, max(c)         from t2 where (b = 'b') group by a1,a2;
a1	a2	max(c)
a	a	h112
a	b	p122
b	a	h212
b	b	p222
c	a	h312
c	b	p322
d	a	h412
d	b	p422
e	a	NULL
select a1,a2,b,max(c),min(c) from t3 where (a2 = 'a') and (b = 'b') group by a1;
a1	a2	b	max(c)	min(c)
a	a	b	h112	e112
b	a	b	h212	e212
c	a	b	h312	e312
select a1,max(c),min(c)      from t3 where (a2 = 'a') and (b = 'b') group by a1;
a1	max(c)	min(c)
a	h112	e112
b	h212	e212
c	h312	e312
explain select a1,a2,b,min(c) from t2 where (a2 = 'a') and b is NULL group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	5	Using where; Using index for group-by
explain select a1,a2,b,max(c) from t2 where (a2 = 'a') and b is NULL group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	584	NULL	5	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t2 where b is NULL group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	10	Using where; Using index for group-by
explain select a1,a2,b,max(c) from t2 where b is NULL group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	584	NULL	10	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where b is NULL group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	10	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where b is NULL group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	NULL	idx_t2_1	651	NULL	10	Using where; Using index for group-by
select a1,a2,b,min(c) from t2 where (a2 = 'a') and b is NULL group by a1;
a1	a2	b	min(c)
a	a	NULL	a777
c	a	NULL	c777
select a1,a2,b,max(c) from t2 where (a2 = 'a') and b is NULL group by a1;
a1	a2	b	max(c)
a	a	NULL	a999
c	a	NULL	c999
select a1,a2,b,min(c) from t2 where b is NULL group by a1,a2;
a1	a2	b	min(c)
a	a	NULL	a777
c	a	NULL	c777
select a1,a2,b,max(c) from t2 where b is NULL group by a1,a2;
a1	a2	b	max(c)
a	a	NULL	a999
c	a	NULL	c999
select a1,a2,b,min(c),max(c) from t2 where b is NULL group by a1,a2;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
c	a	NULL	c777	c999
select a1,a2,b,min(c),max(c) from t2 where b is NULL group by a1,a2;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
c	a	NULL	c777	c999
explain select a1,a2,b,       max(c) from t1 where (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (c > 'f123') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c > 'f123') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (c < 'a0') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (c < 'k321') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c < 'k321') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (c between 'b111' and 'g112') or (c between 'd000' and 'i110') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,       max(c) from t2 where (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,       max(c) from t2 where (c > 'f123') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c > 'f123') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,       max(c) from t2 where (c < 'a0') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,       max(c) from t2 where (c < 'k321') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c < 'k321') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,       max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,       max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
select a1,a2,b,       max(c) from t1 where (c > 'b1') group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,       max(c) from t1 where (c > 'f123') group by a1,a2,b;
a1	a2	b	max(c)
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,       max(c) from t1 where (c < 'a0') group by a1,a2,b;
a1	a2	b	max(c)
select a1,a2,b,min(c),max(c) from t1 where (c < 'a0') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
select a1,a2,b,       max(c) from t1 where (c < 'k321') group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	k121
b	a	a	d211
b	a	b	h212
b	b	a	k221
c	a	a	d311
c	a	b	h312
c	b	a	j321
d	a	a	d411
d	a	b	h412
d	b	a	j421
select a1,a2,b,min(c),max(c) from t1 where (c < 'k321') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	k121
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	k221
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	j321
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	j421
select a1,a2,b,       max(c) from t1 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,       max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t1 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,min(c),max(c) from t1 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	c111	d111
a	a	b	e112	g112
b	a	a	b211	d211
b	a	b	e212	f212
c	a	a	b311	d311
c	a	b	e312	f312
d	a	a	b411	d411
d	a	b	e412	f412
select a1,a2,b,min(c),max(c) from t1 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	a111	c111
b	a	a	a211	c211
c	a	a	a311	c311
d	a	a	a411	c411
d	a	b	g412	g412
d	b	a	k421	k421
select a1,a2,b,min(c),max(c) from t1 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	c111	d111
a	a	b	e112	h112
b	a	a	b211	d211
b	a	b	e212	h212
c	a	a	b311	d311
c	a	b	e312	h312
d	a	a	b411	d411
d	a	b	e412	h412
select a1,a2,b,min(c),max(c) from t1 where (c between 'b111' and 'g112') or (c between 'd000' and 'i110') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	b111	d111
a	a	b	e112	h112
b	a	a	b211	d211
b	a	b	e212	h212
c	a	a	b311	d311
c	a	b	e312	h312
d	a	a	b411	d411
d	a	b	e412	h412
select a1,a2,b,       max(c) from t2 where (c > 'b1') group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	NULL	c999
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	b111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	b211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	NULL	c777	c999
c	a	a	b311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	b411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t2 where (c > 'f123') group by a1,a2,b;
a1	a2	b	max(c)
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t2 where (c > 'f123') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	b	g112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	b	f212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	b	f312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	b	f412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t2 where (c < 'a0') group by a1,a2,b;
a1	a2	b	max(c)
select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
select a1,a2,b,       max(c) from t2 where (c < 'k321') group by a1,a2,b;
a1	a2	b	max(c)
a	a	NULL	a999
a	a	a	d111
a	a	b	h112
a	b	a	k121
b	a	a	d211
b	a	b	h212
b	b	a	k221
c	a	NULL	c999
c	a	a	d311
c	a	b	h312
c	b	a	j321
d	a	a	d411
d	a	b	h412
d	b	a	j421
select a1,a2,b,min(c),max(c) from t2 where (c < 'k321') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	k121
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	k221
c	a	NULL	c777	c999
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	j321
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	j421
select a1,a2,b,       max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
a1	a2	b	max(c)
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	NULL	c999
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t2 where (c < 'a0') or (c > 'b1') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	b111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	b211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	NULL	c777	c999
c	a	a	b311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	b411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,       max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
a1	a2	b	max(c)
a	a	NULL	a999
a	a	a	d111
a	a	b	h112
a	b	a	l121
a	b	b	p122
b	a	a	d211
b	a	b	h212
b	b	a	l221
b	b	b	p222
c	a	NULL	c999
c	a	a	d311
c	a	b	h312
c	b	a	l321
c	b	b	p322
d	a	a	d411
d	a	b	h412
d	b	a	l421
d	b	b	p422
select a1,a2,b,min(c),max(c) from t2 where (c > 'b1') or (c <= 'g1') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
a	a	a	a111	d111
a	a	b	e112	h112
a	b	a	i121	l121
a	b	b	m122	p122
b	a	a	a211	d211
b	a	b	e212	h212
b	b	a	i221	l221
b	b	b	m222	p222
c	a	NULL	c777	c999
c	a	a	a311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	a411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,min(c),max(c) from t2 where (c > 'b111') and (c <= 'g112') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	c111	d111
a	a	b	e112	g112
b	a	a	b211	d211
b	a	b	e212	f212
c	a	NULL	c777	c999
c	a	a	b311	d311
c	a	b	e312	f312
d	a	a	b411	d411
d	a	b	e412	f412
select a1,a2,b,min(c),max(c) from t2 where (c < 'c5') or (c = 'g412') or (c = 'k421') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	NULL	a777	a999
a	a	a	a111	c111
b	a	a	a211	c211
c	a	a	a311	c311
d	a	a	a411	c411
d	a	b	g412	g412
d	b	a	k421	k421
select a1,a2,b,min(c),max(c) from t2 where ((c > 'b111') and (c <= 'g112')) or ((c > 'd000') and (c <= 'i110')) group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	c111	d111
a	a	b	e112	h112
b	a	a	b211	d211
b	a	b	e212	h212
c	a	NULL	c777	c999
c	a	a	b311	d311
c	a	b	e312	h312
d	a	a	b411	d411
d	a	b	e412	h412
explain select a1,a2,b,min(c),max(c) from t1
where exists ( select * from t2 where t2.c = t1.c )
group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	index	NULL	idx_t1_1	651	NULL	128	Using where; Using index
2	DEPENDENT SUBQUERY	t2	index	NULL	idx_t2_1	651	NULL	164	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t1
where exists ( select * from t2 where t2.c > 'b1' )
group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
2	SUBQUERY	t2	index	NULL	idx_t2_1	651	NULL	164	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (c > 'b111') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t1 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	651	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122') or (c < 'h112') or (c = 'c111')) group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t1 where (ord(a1) > 97) and (ord(a2) + ord(a1) > 194) and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,min(c),max(c) from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (a1 >= 'c' or a2 < 'b') and (c > 'b111') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b,min(c) from t2 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t2 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122') or (c < 'h112') or (c = 'c111')) group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
explain select a1,a2,b,min(c) from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	651	NULL	#	Using where; Using index for group-by
select a1,a2,b,min(c),max(c) from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	b	e112	h112
b	a	b	e212	h212
c	a	b	e312	h312
c	b	b	m322	p322
d	a	b	e412	h412
d	b	b	m422	p422
select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
a1	a2	b	min(c)
b	b	a	k221
c	b	a	k321
d	b	a	k421
select a1,a2,b,min(c) from t1 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122') or (c < 'h112') or (c = 'c111')) group by a1,a2,b;
a1	a2	b	min(c)
b	b	a	k221
c	b	a	k321
d	b	a	k421
select a1,a2,b,min(c) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
a1	a2	b	min(c)
select a1,a2,b,min(c) from t1 where (ord(a1) > 97) and (ord(a2) + ord(a1) > 194) and (b = 'c') group by a1,a2,b;
a1	a2	b	min(c)
select a1,a2,b,min(c),max(c) from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	b	e112	h112
b	a	b	e212	h212
c	a	b	e312	h312
c	b	b	m322	p322
d	a	b	e412	h412
d	b	b	m422	p422
e	a	b	NULL	NULL
select a1,a2,b,min(c),max(c) from t2 where (a1 >= 'c' or a2 < 'b') and (c > 'b111') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	a	a	c111	d111
a	a	b	e112	h112
b	a	a	b211	d211
b	a	b	e212	h212
c	a	NULL	c777	c999
c	a	a	b311	d311
c	a	b	e312	h312
c	b	a	i321	l321
c	b	b	m322	p322
d	a	a	b411	d411
d	a	b	e412	h412
d	b	a	i421	l421
d	b	b	m422	p422
select a1,a2,b,min(c),max(c) from t2 where (a2 >= 'b') and (b = 'a') and (c > 'b111') group by a1,a2,b;
a1	a2	b	min(c)	max(c)
a	b	a	i121	l121
b	b	a	i221	l221
c	b	a	i321	l321
d	b	a	i421	l421
select a1,a2,b,min(c) from t2 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c < 'h112') or (c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122')) group by a1,a2,b;
a1	a2	b	min(c)
b	b	a	k221
c	b	a	k321
d	b	a	k421
select a1,a2,b,min(c) from t2 where ((a1 > 'a') or (a1 < '9'))  and ((a2 >= 'b') and (a2 < 'z')) and (b = 'a') and ((c = 'j121') or (c > 'k121' and c < 'm122') or (c > 'o122') or (c < 'h112') or (c = 'c111')) group by a1,a2,b;
a1	a2	b	min(c)
b	b	a	k221
c	b	a	k321
d	b	a	k421
select a1,a2,b,min(c) from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
a1	a2	b	min(c)
explain select a1,a2,b from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_1	651	NULL	128	Using where; Using index
explain select a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select a1,a2,b from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_2	584	NULL	#	Using where; Using index
explain select a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	#	Using where; Using index
explain select a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
select a1,a2,b from t1 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
a1	a2	b
a	a	b
b	a	b
c	a	b
c	b	b
d	a	b
d	b	b
select a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
a1	a2	b
a	b	a
b	b	a
c	b	a
d	b	a
select a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
a1	a2	b	c
a	b	a	i121
select a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
a1	a2	b
select a1,a2,b from t2 where (a1 >= 'c' or a2 < 'b') and (b > 'a') group by a1,a2,b;
a1	a2	b
a	a	b
b	a	b
c	a	b
c	b	b
d	a	b
d	b	b
e	a	b
select a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
a1	a2	b
a	b	a
b	b	a
c	b	a
d	b	a
select a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
a1	a2	b	c
a	b	a	i121
select a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
a1	a2	b
explain select distinct a1,a2,b from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
explain select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain extended select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	NULL	idx_t1_1	651	NULL	128	50.78	Using where; Using index
Warnings:
Note	1003	select distinct `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where ((`test`.`t1`.`a2` >= 'b') and (`test`.`t1`.`b` = 'a') and (`test`.`t1`.`c` = 'i121'))
explain select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select distinct b from t1 where (a2 >= 'b') and (b = 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_2	585	NULL	128	Using where; Using index
explain select distinct a1,a2,b from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	#	Using index
explain select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	#	Using where; Using index
explain extended select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	164	50.61	Using where; Using index
Warnings:
Note	1003	select distinct `test`.`t2`.`a1` AS `a1`,`test`.`t2`.`a2` AS `a2`,`test`.`t2`.`b` AS `b`,`test`.`t2`.`c` AS `c` from `test`.`t2` where ((`test`.`t2`.`a2` >= 'b') and (`test`.`t2`.`b` = 'a') and (`test`.`t2`.`c` = 'i121'))
explain select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select distinct b from t2 where (a2 >= 'b') and (b = 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	164	Using where; Using index
select distinct a1,a2,b from t1;
a1	a2	b
a	a	a
a	a	b
a	b	a
a	b	b
b	a	a
b	a	b
b	b	a
b	b	b
c	a	a
c	a	b
c	b	a
c	b	b
d	a	a
d	a	b
d	b	a
d	b	b
select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a');
a1	a2	b
a	b	a
b	b	a
c	b	a
d	b	a
select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
a1	a2	b	c
a	b	a	i121
select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
a1	a2	b
select distinct b from t1 where (a2 >= 'b') and (b = 'a');
b
a
select distinct a1,a2,b from t2;
a1	a2	b
a	a	NULL
a	a	a
a	a	b
a	b	a
a	b	b
b	a	a
b	a	b
b	b	a
b	b	b
c	a	NULL
c	a	a
c	a	b
c	b	a
c	b	b
d	a	a
d	a	b
d	b	a
d	b	b
e	a	a
e	a	b
select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a');
a1	a2	b
a	b	a
b	b	a
c	b	a
d	b	a
select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
a1	a2	b	c
a	b	a	i121
select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
a1	a2	b
select distinct b from t2 where (a2 >= 'b') and (b = 'a');
b
a
select distinct t_00.a1
from t1 t_00
where exists ( select * from t2 where a1 = t_00.a1 );
a1
a
b
c
d
select distinct a1,a1 from t1;
a1	a1
a	a
b	b
c	c
d	d
select distinct a2,a1,a2,a1 from t1;
a2	a1	a2	a1
a	a	a	a
b	a	b	a
a	b	a	b
b	b	b	b
a	c	a	c
b	c	b	c
a	d	a	d
b	d	b	d
select distinct t1.a1,t2.a1 from t1,t2;
a1	a1
a	a
a	b
a	c
a	d
a	e
b	a
b	b
b	c
b	d
b	e
c	a
c	b
c	c
c	d
c	e
d	a
d	b
d	c
d	d
d	e
explain select distinct a1,a2,b from t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using index for group-by
explain select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by
explain select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_1	651	NULL	128	Using where; Using index
explain select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select distinct b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	17	Using where; Using index for group-by; Using temporary; Using filesort
explain select distinct a1,a2,b from t2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	#	Using index
explain select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	#	Using where; Using index
explain select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	#	Using where; Using index
explain select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	idx_t2_0,idx_t2_1,idx_t2_2	idx_t2_1	584	NULL	#	Using where; Using index for group-by
explain select distinct b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_2	584	NULL	#	Using where; Using index; Using temporary; Using filesort
select distinct a1,a2,b from t1;
a1	a2	b
a	a	a
a	a	b
a	b	a
a	b	b
b	a	a
b	a	b
b	b	a
b	b	b
c	a	a
c	a	b
c	b	a
c	b	b
d	a	a
d	a	b
d	b	a
d	b	b
select distinct a1,a2,b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
a1	a2	b
a	b	a
b	b	a
c	b	a
d	b	a
select distinct a1,a2,b,c from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
a1	a2	b	c
a	b	a	i121
select distinct a1,a2,b from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
a1	a2	b
select distinct b from t1 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
b
a
select distinct a1,a2,b from t2;
a1	a2	b
a	a	NULL
a	a	a
a	a	b
a	b	a
a	b	b
b	a	a
b	a	b
b	b	a
b	b	b
c	a	NULL
c	a	a
c	a	b
c	b	a
c	b	b
d	a	a
d	a	b
d	b	a
d	b	b
e	a	a
e	a	b
select distinct a1,a2,b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
a1	a2	b
a	b	a
b	b	a
c	b	a
d	b	a
select distinct a1,a2,b,c from t2 where (a2 >= 'b') and (b = 'a') and (c = 'i121') group by a1,a2,b;
a1	a2	b	c
a	b	a	i121
select distinct a1,a2,b from t2 where (a1 > 'a') and (a2 > 'a') and (b = 'c') group by a1,a2,b;
a1	a2	b
select distinct b from t2 where (a2 >= 'b') and (b = 'a') group by a1,a2,b;
b
a
explain select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_2	585	NULL	128	Using where; Using index
explain select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_1	651	NULL	128	Using where; Using index
explain extended select count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	585	NULL	128	75.00	Using where; Using index
Warnings:
Note	1003	select count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`b` = 'c'))
explain select count(distinct b) from t1 where (a2 >= 'b') and (b = 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_2	585	NULL	128	Using where; Using index
explain extended select ord(a1) + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_2	585	NULL	128	75.00	Using where; Using index
Warnings:
Note	1003	select (ord(`test`.`t1`.`a1`) + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`)) AS `ord(a1) + count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
count(distinct a1,a2,b)
4
select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
count(distinct a1,a2,b,c)
1
select count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
count(distinct a1,a2,b)
0
select count(distinct b) from t1 where (a2 >= 'b') and (b = 'a');
count(distinct b)
1
select ord(a1) + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
ord(a1) + count(distinct a1,a2,b)
104
explain select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select concat(a1,min(c)),b from t1 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select concat(a1,min(c)),b,max(c) from t1 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select concat(a1,a2),b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	585	NULL	13	Using where; Using index for group-by
explain select concat(ord(min(b)),ord(max(b))),min(b),max(b) from t1 group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	585	NULL	9	Using index for group-by
select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
a1	a2	b	concat(min(c), max(c))
a	a	a	a111d111
a	a	b	e112h112
a	b	a	i121l121
a	b	b	m122p122
b	a	a	a211d211
b	a	b	e212h212
b	b	a	i221l221
b	b	b	m222p222
c	a	a	a311d311
c	a	b	e312h312
c	b	a	i321l321
c	b	b	m322p322
select concat(a1,min(c)),b from t1 where a1 < 'd' group by a1,a2,b;
concat(a1,min(c))	b
aa111	a
ae112	b
ai121	a
am122	b
ba211	a
be212	b
bi221	a
bm222	b
ca311	a
ce312	b
ci321	a
cm322	b
select concat(a1,min(c)),b,max(c) from t1 where a1 < 'd' group by a1,a2,b;
concat(a1,min(c))	b	max(c)
aa111	a	d111
ae112	b	h112
ai121	a	l121
am122	b	p122
ba211	a	d211
be212	b	h212
bi221	a	l221
bm222	b	p222
ca311	a	d311
ce312	b	h312
ci321	a	l321
cm322	b	p322
select concat(a1,a2),b,min(c),max(c) from t1 where a1 < 'd' group by a1,a2,b;
concat(a1,a2)	b	min(c)	max(c)
aa	a	a111	d111
aa	b	e112	h112
ab	a	i121	l121
ab	b	m122	p122
ba	a	a211	d211
ba	b	e212	h212
bb	a	i221	l221
bb	b	m222	p222
ca	a	a311	d311
ca	b	e312	h312
cb	a	i321	l321
cb	b	m322	p322
select concat(ord(min(b)),ord(max(b))),min(b),max(b) from t1 group by a1,a2;
concat(ord(min(b)),ord(max(b)))	min(b)	max(b)
9798	a	b
9798	a	b
9798	a	b
9798	a	b
9798	a	b
9798	a	b
9798	a	b
9798	a	b
explain select a1,a2,b,d,min(c),max(c) from t1 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	128	Using temporary; Using filesort
explain select a1,a2,b,d from t1 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	128	Using temporary; Using filesort
explain extended select a1,a2,min(b),max(b) from t1
where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (c > 'a111') group by a1,a2;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	128	49.22	Using where; Using index
Warnings:
Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,min(`test`.`t1`.`b`) AS `min(b)`,max(`test`.`t1`.`b`) AS `max(b)` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`c` > 'a111')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`
explain extended select a1,a2,b,min(c),max(c) from t1
where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (d > 'xy2') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	ALL	idx_t1_0,idx_t1_1,idx_t1_2	NULL	NULL	NULL	128	49.22	Using where; Using temporary; Using filesort
Warnings:
Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,min(`test`.`t1`.`c`) AS `min(c)`,max(`test`.`t1`.`c`) AS `max(c)` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`d` > 'xy2')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
explain extended select a1,a2,b,c from t1
where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (d > 'xy2') group by a1,a2,b,c;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	ALL	idx_t1_0,idx_t1_1,idx_t1_2	NULL	NULL	NULL	128	49.22	Using where; Using temporary; Using filesort
Warnings:
Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b`,`test`.`t1`.`c` AS `c` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`d` > 'xy2')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`,`test`.`t1`.`c`
explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') or (b < 'b') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	164	Using where; Using index
explain extended select a1,a2,b from t1 where (a1 = 'b' or a1 = 'd' or a1 = 'a' or a1 = 'c') and (a2 > 'a') and (c > 'a111') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	128	49.22	Using where; Using index
Warnings:
Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,`test`.`t1`.`b` AS `b` from `test`.`t1` where (((`test`.`t1`.`a1` = 'b') or (`test`.`t1`.`a1` = 'd') or (`test`.`t1`.`a1` = 'a') or (`test`.`t1`.`a1` = 'c')) and (`test`.`t1`.`a2` > 'a') and (`test`.`t1`.`c` > 'a111')) group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
explain select a1,a2,min(b),c from t2 where (a2 = 'a') and (c = 'a111') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	164	Using where; Using index
select a1,a2,min(b),c from t2 where (a2 = 'a') and (c = 'a111') group by a1;
a1	a2	min(b)	c
a	a	a	a111
explain select a1,a2,b,max(c),min(c) from t2 where (a2 = 'a') and (b = 'b') or (b = 'a') group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	164	Using where; Using index
explain select a1,a2,b,min(c),max(c) from t2
where (c > 'a000') and (c <= 'd999') and (c like '_8__') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	index	NULL	idx_t2_1	651	NULL	164	Using where; Using index
explain select a1, a2, b, c, min(d), max(d) from t1 group by a1,a2,b,c;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	128	Using temporary; Using filesort
explain select a1,a2,count(a2) from t1 group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_2	585	NULL	128	Using index
explain extended select a1,a2,count(a2) from t1 where (a1 > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	128	75.00	Using where; Using index
Warnings:
Note	1003	select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2`,count(`test`.`t1`.`a2`) AS `count(a2)` from `test`.`t1` where (`test`.`t1`.`a1` > 'a') group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
explain extended select sum(ord(a1)) from t1 where (a1 > 'a') group by a1,a2,b;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	index	idx_t1_0,idx_t1_1,idx_t1_2	idx_t1_1	651	NULL	128	75.00	Using where; Using index
Warnings:
Note	1003	select sum(ord(`test`.`t1`.`a1`)) AS `sum(ord(a1))` from `test`.`t1` where (`test`.`t1`.`a1` > 'a') group by `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`
explain select distinct(a1) from t1 where ord(a2) = 98;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx_t1_2	585	NULL	128	Using where; Using index
select distinct(a1) from t1 where ord(a2) = 98;
a1
a
b
c
d
explain select a1 from t1 where a2 = 'b' group by a1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	518	NULL	5	Using where; Using index for group-by
select a1 from t1 where a2 = 'b' group by a1;
a1
a
b
c
d
explain select distinct a1 from t1 where a2 = 'b';
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	idx_t1_1	518	NULL	5	Using where; Using index for group-by
select distinct a1 from t1 where a2 = 'b';
a1
a
b
c
d
drop table t1,t2,t3;
create TEMPORARY table t1 (c1 int not null,c2 int not null, primary key(c1,c2)) ENGINE=MYISAM;
insert into t1 (c1,c2) values
(10,1),(10,2),(10,3),(20,4),(20,5),(20,6),(30,7),(30,8),(30,9);
select distinct c1, c2 from t1 order by c2;
c1	c2
10	1
10	2
10	3
20	4
20	5
20	6
30	7
30	8
30	9
select c1,min(c2) as c2 from t1 group by c1 order by c2;
c1	c2
10	1
20	4
30	7
select c1,c2 from t1 group by c1,c2 order by c2;
c1	c2
10	1
10	2
10	3
20	4
20	5
20	6
30	7
30	8
30	9
drop table t1;
CREATE TABLE t1 (a varchar(5), b int, PRIMARY KEY (a,b));
INSERT INTO t1 VALUES ('AA',1), ('AA',2), ('AA',3), ('BB',1), ('AA',4);
ALTER TABLE t1 ENGINE="DEFAULT";
SELECT a FROM t1 WHERE a='AA' GROUP BY a;
a
AA
SELECT a FROM t1 WHERE a='BB' GROUP BY a;
a
BB
EXPLAIN SELECT a FROM t1 WHERE a='AA' GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	PRIMARY	PRIMARY	22	const	2	Using where; Using index
EXPLAIN SELECT a FROM t1 WHERE a='BB' GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ref	PRIMARY	PRIMARY	22	const	1	Using where; Using index
SELECT DISTINCT a FROM t1 WHERE a='BB';
a
BB
SELECT DISTINCT a FROM t1 WHERE a LIKE 'B%';
a
BB
SELECT a FROM t1 WHERE a LIKE 'B%' GROUP BY a;
a
BB
DROP TABLE t1;
CREATE TABLE t1 (a varchar(64) NOT NULL default '', PRIMARY KEY(a));
INSERT INTO t1 (a) VALUES 
(''), ('CENTRAL'), ('EASTERN'), ('GREATER LONDON'),
('NORTH CENTRAL'), ('NORTH EAST'), ('NORTH WEST'), ('SCOTLAND'),
('SOUTH EAST'), ('SOUTH WEST'), ('WESTERN');
EXPLAIN SELECT DISTINCT a,a FROM t1 ORDER BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	PRIMARY	258	NULL	12	Using index for group-by
SELECT DISTINCT a,a FROM t1 ORDER BY a;
a	a
	
CENTRAL	CENTRAL
EASTERN	EASTERN
GREATER LONDON	GREATER LONDON
NORTH CENTRAL	NORTH CENTRAL
NORTH EAST	NORTH EAST
NORTH WEST	NORTH WEST
SCOTLAND	SCOTLAND
SOUTH EAST	SOUTH EAST
SOUTH WEST	SOUTH WEST
WESTERN	WESTERN
DROP TABLE t1;
CREATE TABLE t1 (id1 INT, id2 INT);
CREATE TABLE t2 (id2 INT, id3 INT, id5 INT);
CREATE TABLE t3 (id3 INT, id4 INT);
CREATE TABLE t4 (id4 INT);
CREATE TABLE t5 (id5 INT, id6 INT);
CREATE TABLE t6 (id6 INT);
INSERT INTO t1 VALUES(1,1);
INSERT INTO t2 VALUES(1,1,1);
INSERT INTO t3 VALUES(1,1);
INSERT INTO t4 VALUES(1);
INSERT INTO t5 VALUES(1,1);
INSERT INTO t6 VALUES(1);
SELECT * FROM
t1
NATURAL JOIN
(t2 JOIN (t3 NATURAL JOIN t4, t5 NATURAL JOIN t6)
ON (t3.id3 = t2.id3 AND t5.id5 = t2.id5));
id2	id1	id3	id5	id4	id3	id6	id5
1	1	1	1	1	1	1	1
SELECT * FROM
t1
NATURAL JOIN
(((t3 NATURAL JOIN t4) join (t5 NATURAL JOIN t6) on t3.id4 = t5.id5) JOIN t2
ON (t3.id3 = t2.id3 AND t5.id5 = t2.id5));
id2	id1	id4	id3	id6	id5	id3	id5
1	1	1	1	1	1	1	1
SELECT * FROM t1 NATURAL JOIN ((t3 join (t5 NATURAL JOIN t6)) JOIN t2);
id2	id1	id3	id4	id6	id5	id3	id5
1	1	1	1	1	1	1	1
SELECT * FROM
(t2 JOIN (t3 NATURAL JOIN t4, t5 NATURAL JOIN t6)
ON (t3.id3 = t2.id3 AND t5.id5 = t2.id5))
NATURAL JOIN
t1;
id2	id3	id5	id4	id3	id6	id5	id1
1	1	1	1	1	1	1	1
SELECT * FROM
(t2 JOIN ((t3 NATURAL JOIN t4) join (t5 NATURAL JOIN t6)))
NATURAL JOIN
t1;
id2	id3	id5	id4	id3	id6	id5	id1
1	1	1	1	1	1	1	1
DROP TABLE t1,t2,t3,t4,t5,t6;
CREATE TABLE t1 (a int, b int, PRIMARY KEY (a,b), KEY b (b));
INSERT INTO t1 VALUES (1,1),(1,2),(1,0),(1,3);
explain SELECT MAX(b), a FROM t1 WHERE b < 2 AND a = 1 GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	PRIMARY,b	PRIMARY	8	NULL	1	Using where; Using index for group-by
SELECT MAX(b), a FROM t1 WHERE b < 2 AND a = 1 GROUP BY a;
MAX(b)	a
1	1
SELECT MIN(b), a FROM t1 WHERE b > 1 AND a = 1 GROUP BY a;
MIN(b)	a
2	1
CREATE TABLE t2 (a int, b int, c int, PRIMARY KEY (a,b,c));
INSERT INTO t2 SELECT a,b,b FROM t1;
explain SELECT MIN(c) FROM t2 WHERE b = 2 and a = 1 and c > 1 GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t2	range	PRIMARY	PRIMARY	12	NULL	1	Using where; Using index for group-by
SELECT MIN(c) FROM t2 WHERE b = 2 and a = 1 and c > 1 GROUP BY a;
MIN(c)
2
DROP TABLE t1,t2;
CREATE TABLE t1 (a INT, b INT, INDEX (a,b));
INSERT INTO t1 (a, b) VALUES (1,1), (1,2), (1,3), (1,4), (1,5),
(2,2), (2,3), (2,1), (3,1), (4,1), (4,2), (4,3), (4,4), (4,5), (4,6);
EXPLAIN SELECT max(b), a FROM t1 GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	a	10	NULL	15	Using index
FLUSH STATUS;
SELECT max(b), a FROM t1 GROUP BY a;
max(b)	a
5	1
3	2
1	3
6	4
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	2
Handler_read_next	15
EXPLAIN SELECT max(b), a FROM t1 GROUP BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	a	10	NULL	15	Using index
FLUSH STATUS;
CREATE TABLE t2 SELECT max(b), a FROM t1 GROUP BY a;
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	2
Handler_read_next	15
FLUSH STATUS;
SELECT * FROM (SELECT max(b), a FROM t1 GROUP BY a) b;
max(b)	a
5	1
3	2
1	3
6	4
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	2
Handler_read_next	15
FLUSH STATUS;
(SELECT max(b), a FROM t1 GROUP BY a) UNION 
(SELECT max(b), a FROM t1 GROUP BY a);
max(b)	a
5	1
3	2
1	3
6	4
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	23
Handler_read_next	0
EXPLAIN (SELECT max(b), a FROM t1 GROUP BY a) UNION 
(SELECT max(b), a FROM t1 GROUP BY a);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1	range	NULL	a	5	NULL	3	Using index for group-by
2	UNION	t1	range	NULL	a	5	NULL	3	Using index for group-by
NULL	UNION RESULT	<union1,2>	ALL	NULL	NULL	NULL	NULL	NULL	
EXPLAIN SELECT (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) x
FROM t1 AS t1_outer;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1_outer	index	NULL	a	10	NULL	15	Using index
2	SUBQUERY	t1	range	NULL	a	5	NULL	3	Using index for group-by
EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE EXISTS 
(SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1_outer	index	NULL	a	10	NULL	15	Using index
2	SUBQUERY	t1	index	NULL	a	10	NULL	15	Using index
EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
(SELECT max(b) FROM t1 GROUP BY a HAVING a < 2) > 12;
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	SUBQUERY	t1	range	NULL	a	5	NULL	3	Using index for group-by
EXPLAIN SELECT 1 FROM t1 AS t1_outer WHERE 
a IN (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1_outer	index	NULL	a	10	NULL	15	Using where; Using index
2	SUBQUERY	t1	range	NULL	a	5	NULL	3	Using index for group-by
EXPLAIN SELECT 1 FROM t1 AS t1_outer GROUP BY a HAVING 
a > (SELECT max(b) FROM t1 GROUP BY a HAVING a < 2);
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1_outer	range	NULL	a	5	NULL	3	Using index for group-by
2	SUBQUERY	t1	range	NULL	a	5	NULL	3	Using index for group-by
EXPLAIN SELECT 1 FROM t1 AS t1_outer1 JOIN t1 AS t1_outer2 
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
2	SUBQUERY	t1	range	NULL	a	5	NULL	3	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;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	PRIMARY	t1_outer2	index	NULL	a	10	NULL	15	Using index
2	SUBQUERY	t1_outer	index	NULL	a	10	NULL	15	Using index
3	SUBQUERY	t1	range	NULL	a	5	NULL	3	Using index for group-by
CREATE TABLE t3 LIKE t1;
FLUSH STATUS;
INSERT INTO t3 SELECT a,MAX(b) FROM t1 GROUP BY a;
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	12
Handler_read_next	0
DELETE FROM t3;
FLUSH STATUS;
INSERT INTO t3 SELECT 1, (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) 
FROM t1 LIMIT 1;
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	13
Handler_read_next	0
FLUSH STATUS;
DELETE FROM t3 WHERE (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) > 10000;
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	11
Handler_read_next	0
FLUSH STATUS;
DELETE FROM t3 WHERE (SELECT (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) x 
FROM t1) > 10000;
ERROR 21000: Subquery returns more than 1 row
SHOW STATUS LIKE 'handler_read__e%';
Variable_name	Value
Handler_read_key	13
Handler_read_next	1
DROP TABLE t1,t2,t3;
CREATE TABLE t1 (a int, INDEX idx(a));
INSERT INTO t1 VALUES
(4), (2), (1), (2), (4), (2), (1), (4),
(4), (2), (1), (2), (2), (4), (1), (4);
EXPLAIN SELECT DISTINCT(a) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx	5	NULL	16	Using index
SELECT DISTINCT(a) FROM t1;
a
1
2
4
EXPLAIN SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	idx	5	NULL	16	Using index
SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;
a
1
2
4
DROP TABLE t1;
CREATE TABLE t1 (a INT, b INT);
INSERT INTO t1 (a, b) VALUES (1,1), (1,2), (1,3);
INSERT INTO t1 SELECT a + 1, b FROM t1;
INSERT INTO t1 SELECT a + 2, b FROM t1;
EXPLAIN
SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	12	Using temporary; Using filesort
SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
a	MIN(b)	MAX(b)
4	1	3
3	1	3
2	1	3
1	1	3
CREATE INDEX break_it ON t1 (a, b);
EXPLAIN
SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	break_it	10	NULL	3	Using index for group-by
SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a;
a	MIN(b)	MAX(b)
1	1	3
2	1	3
3	1	3
4	1	3
EXPLAIN
SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	break_it	10	NULL	3	Using index for group-by; Using temporary; Using filesort
SELECT a, MIN(b), MAX(b) FROM t1 GROUP BY a ORDER BY a DESC;
a	MIN(b)	MAX(b)
4	1	3
3	1	3
2	1	3
1	1	3
EXPLAIN
SELECT a, MIN(b), MAX(b), AVG(b) FROM t1 GROUP BY a ORDER BY a DESC;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	index	NULL	break_it	10	NULL	12	Using index
SELECT a, MIN(b), MAX(b), AVG(b) FROM t1 GROUP BY a ORDER BY a DESC;
a	MIN(b)	MAX(b)	AVG(b)
4	1	3	2.0000
3	1	3	2.0000
2	1	3	2.0000
1	1	3	2.0000
DROP TABLE t1;
CREATE TABLE t1 (a int, b int, c int, d int,
KEY foo (c,d,a,b), KEY bar (c,a,b,d));
INSERT INTO t1 VALUES (1, 1, 1, 1), (1, 1, 1, 2), (1, 1, 1, 3), (1, 1, 1, 4);
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT * FROM t1;
INSERT INTO t1 SELECT a,b,c+1,d FROM t1;
EXPLAIN SELECT DISTINCT c FROM t1 WHERE d=4;
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	t1	range	NULL	foo	10	NULL	17	Using where; Using index for group-by
SELECT DISTINCT c FROM t1 WHERE d=4;
c
1
2
DROP TABLE t1;