mirror of
				https://github.com/MariaDB/server.git
				synced 2025-11-03 14:33:32 +03:00 
			
		
		
		
	
		
			
				
	
	
		
			369 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			369 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
drop table if exists t1,t2;
 | 
						|
create table t1 (a int not null,b int not null, primary key using HASH (a)) engine=heap comment="testing heaps" avg_row_length=100 min_rows=1 max_rows=100;
 | 
						|
insert into t1 values(1,1),(2,2),(3,3),(4,4);
 | 
						|
delete from t1 where a=1 or a=0;
 | 
						|
show keys from t1;
 | 
						|
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 | 
						|
t1	0	PRIMARY	1	a	NULL	3	NULL	NULL		HASH	
 | 
						|
select * from t1;
 | 
						|
a	b
 | 
						|
2	2
 | 
						|
3	3
 | 
						|
4	4
 | 
						|
select * from t1 where a=4;
 | 
						|
a	b
 | 
						|
4	4
 | 
						|
update t1 set b=5 where a=4;
 | 
						|
update t1 set b=b+1 where a>=3;
 | 
						|
replace t1 values (3,3);
 | 
						|
select * from t1;
 | 
						|
a	b
 | 
						|
2	2
 | 
						|
3	3
 | 
						|
4	6
 | 
						|
alter table t1 add c int not null, add key using HASH (c,a);
 | 
						|
drop table t1;
 | 
						|
create table t1 (a int not null,b int not null, primary key using HASH (a)) engine=heap comment="testing heaps";
 | 
						|
insert into t1 values(1,1),(2,2),(3,3),(4,4);
 | 
						|
delete from t1 where a > 0;
 | 
						|
select * from t1;
 | 
						|
a	b
 | 
						|
drop table t1;
 | 
						|
create table t1 (a int not null,b int not null, primary key using HASH (a)) engine=heap comment="testing heaps";
 | 
						|
insert into t1 values(1,1),(2,2),(3,3),(4,4);
 | 
						|
alter table t1 modify a int not null auto_increment, engine=myisam, comment="new myisam table";
 | 
						|
select * from t1;
 | 
						|
a	b
 | 
						|
1	1
 | 
						|
2	2
 | 
						|
3	3
 | 
						|
4	4
 | 
						|
drop table t1;
 | 
						|
create table t1 (a int not null) engine=heap;
 | 
						|
insert into t1 values (869751),(736494),(226312),(802616),(728912);
 | 
						|
select * from t1 where a > 736494;
 | 
						|
a
 | 
						|
869751
 | 
						|
802616
 | 
						|
alter table t1 add unique uniq_id using HASH (a);
 | 
						|
select * from t1 where a > 736494;
 | 
						|
a
 | 
						|
869751
 | 
						|
802616
 | 
						|
select * from t1 where a = 736494;
 | 
						|
a
 | 
						|
736494
 | 
						|
select * from t1 where a=869751 or a=736494;
 | 
						|
a
 | 
						|
736494
 | 
						|
869751
 | 
						|
select * from t1 where a in (869751,736494,226312,802616);
 | 
						|
a
 | 
						|
226312
 | 
						|
736494
 | 
						|
802616
 | 
						|
869751
 | 
						|
alter table t1 engine=myisam;
 | 
						|
explain select * from t1 where a in (869751,736494,226312,802616);
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	range	uniq_id	uniq_id	4	NULL	4	Using where; Using index
 | 
						|
drop table t1;
 | 
						|
create table t1 (x int not null, y int not null, key x  using HASH (x), unique y  using HASH (y))
 | 
						|
engine=heap;
 | 
						|
insert into t1 values (1,1),(2,2),(1,3),(2,4),(2,5),(2,6);
 | 
						|
select * from t1 where x=1;
 | 
						|
x	y
 | 
						|
1	3
 | 
						|
1	1
 | 
						|
select * from t1,t1 as t2 where t1.x=t2.y;
 | 
						|
x	y	x	y
 | 
						|
1	1	1	1
 | 
						|
2	2	2	2
 | 
						|
1	3	1	1
 | 
						|
2	4	2	2
 | 
						|
2	5	2	2
 | 
						|
2	6	2	2
 | 
						|
explain select * from t1,t1 as t2 where t1.x=t2.y;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ALL	x	NULL	NULL	NULL	6	
 | 
						|
1	SIMPLE	t2	eq_ref	y	y	4	test.t1.x	1	
 | 
						|
drop table t1;
 | 
						|
create table t1 (a int) engine=heap;
 | 
						|
insert into t1 values(1);
 | 
						|
select max(a) from t1;
 | 
						|
max(a)
 | 
						|
1
 | 
						|
drop table t1;
 | 
						|
CREATE TABLE t1 ( a int not null default 0, b int not null default 0,  key  using HASH (a),  key  using HASH (b)  ) ENGINE=HEAP;
 | 
						|
insert into t1 values(1,1),(1,2),(2,3),(1,3),(1,4),(1,5),(1,6);
 | 
						|
select * from t1 where a=1;
 | 
						|
a	b
 | 
						|
1	6
 | 
						|
1	5
 | 
						|
1	4
 | 
						|
1	3
 | 
						|
1	2
 | 
						|
1	1
 | 
						|
insert into t1 values(1,1),(1,2),(2,3),(1,3),(1,4),(1,5),(1,6);
 | 
						|
select * from t1 where a=1;
 | 
						|
a	b
 | 
						|
1	6
 | 
						|
1	5
 | 
						|
1	4
 | 
						|
1	3
 | 
						|
1	2
 | 
						|
1	1
 | 
						|
1	6
 | 
						|
1	5
 | 
						|
1	4
 | 
						|
1	3
 | 
						|
1	2
 | 
						|
1	1
 | 
						|
drop table t1;
 | 
						|
create table t1 (id int unsigned not null, primary key  using HASH (id)) engine=HEAP;
 | 
						|
insert into t1 values(1);
 | 
						|
select max(id) from t1;
 | 
						|
max(id)
 | 
						|
1
 | 
						|
insert into t1 values(2);
 | 
						|
select max(id) from t1;
 | 
						|
max(id)
 | 
						|
2
 | 
						|
replace into t1 values(1);
 | 
						|
drop table t1;
 | 
						|
create table t1 (n int) engine=heap;
 | 
						|
drop table t1;
 | 
						|
create table t1 (n int) engine=heap;
 | 
						|
drop table if exists t1;
 | 
						|
CREATE table t1(f1 int not null,f2 char(20) not 
 | 
						|
null,index(f2)) engine=heap;
 | 
						|
INSERT into t1 set f1=12,f2="bill";
 | 
						|
INSERT into t1 set f1=13,f2="bill";
 | 
						|
INSERT into t1 set f1=14,f2="bill";
 | 
						|
INSERT into t1 set f1=15,f2="bill";
 | 
						|
INSERT into t1 set f1=16,f2="ted";
 | 
						|
INSERT into t1 set f1=12,f2="ted";
 | 
						|
INSERT into t1 set f1=12,f2="ted";
 | 
						|
INSERT into t1 set f1=12,f2="ted";
 | 
						|
INSERT into t1 set f1=12,f2="ted";
 | 
						|
delete from t1 where f2="bill";
 | 
						|
select * from t1;
 | 
						|
f1	f2
 | 
						|
16	ted
 | 
						|
12	ted
 | 
						|
12	ted
 | 
						|
12	ted
 | 
						|
12	ted
 | 
						|
drop table t1;
 | 
						|
create table t1 (btn char(10) not null, key using HASH (btn)) engine=heap;
 | 
						|
insert into t1 values ("hello"),("hello"),("hello"),("hello"),("hello"),("a"),("b"),("c"),("d"),("e"),("f"),("g"),("h"),("i");
 | 
						|
explain select * from t1 where btn like "q%";
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ALL	btn	NULL	NULL	NULL	14	Using where
 | 
						|
select * from t1 where btn like "q%";
 | 
						|
btn
 | 
						|
alter table t1 add column new_col char(1) not null, add key using HASH (btn,new_col), drop key btn;
 | 
						|
update t1 set new_col=left(btn,1);
 | 
						|
explain select * from t1 where btn="a";
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ALL	btn	NULL	NULL	NULL	11	Using where
 | 
						|
explain select * from t1 where btn="a" and new_col="a";
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	btn	btn	11	const,const	1	Using where
 | 
						|
drop table t1;
 | 
						|
CREATE TABLE t1 (
 | 
						|
a int default NULL,
 | 
						|
b int default NULL,
 | 
						|
KEY a using HASH (a),
 | 
						|
UNIQUE b using HASH (b)
 | 
						|
) engine=heap;
 | 
						|
INSERT INTO t1 VALUES (NULL,99),(99,NULL),(1,1),(2,2),(1,3);
 | 
						|
SELECT * FROM t1 WHERE a=NULL;
 | 
						|
a	b
 | 
						|
explain SELECT * FROM t1 WHERE a IS NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	5	const	1	Using where
 | 
						|
SELECT * FROM t1 WHERE a<=>NULL;
 | 
						|
a	b
 | 
						|
NULL	99
 | 
						|
SELECT * FROM t1 WHERE b=NULL;
 | 
						|
a	b
 | 
						|
explain SELECT * FROM t1 WHERE b IS NULL;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	b	b	5	const	1	Using where
 | 
						|
SELECT * FROM t1 WHERE b<=>NULL;
 | 
						|
a	b
 | 
						|
99	NULL
 | 
						|
INSERT INTO t1 VALUES (1,3);
 | 
						|
ERROR 23000: Duplicate entry '3' for key 1
 | 
						|
DROP TABLE t1;
 | 
						|
CREATE TABLE t1 (a int not null, primary key using HASH (a)) engine=heap;
 | 
						|
INSERT into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11);
 | 
						|
DELETE from t1 where a < 100;
 | 
						|
SELECT * from t1;
 | 
						|
a
 | 
						|
DROP TABLE t1;
 | 
						|
create table t1
 | 
						|
(
 | 
						|
a char(8) not null,
 | 
						|
b char(20) not null,
 | 
						|
c int not null,
 | 
						|
key (a)
 | 
						|
) engine=heap;
 | 
						|
insert into t1 values ('aaaa', 'prefill-hash=5',0);
 | 
						|
insert into t1 values ('aaab', 'prefill-hash=0',0);
 | 
						|
insert into t1 values ('aaac', 'prefill-hash=7',0);
 | 
						|
insert into t1 values ('aaad', 'prefill-hash=2',0);
 | 
						|
insert into t1 values ('aaae', 'prefill-hash=1',0);
 | 
						|
insert into t1 values ('aaaf', 'prefill-hash=4',0);
 | 
						|
insert into t1 values ('aaag', 'prefill-hash=3',0);
 | 
						|
insert into t1 values ('aaah', 'prefill-hash=6',0);
 | 
						|
explain select * from t1 where a='aaaa';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	1	Using where
 | 
						|
explain select * from t1 where a='aaab';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	1	Using where
 | 
						|
explain select * from t1 where a='aaac';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	1	Using where
 | 
						|
explain select * from t1 where a='aaad';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	1	Using where
 | 
						|
insert into t1 select * from t1;
 | 
						|
flush tables;
 | 
						|
explain select * from t1 where a='aaaa';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaab';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaac';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaad';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
flush tables;
 | 
						|
explain select * from t1 where a='aaaa';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaab';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaac';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaad';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
create table t2 as select * from t1;
 | 
						|
delete from t1;
 | 
						|
insert into t1 select * from t2;
 | 
						|
explain select * from t1 where a='aaaa';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaab';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaac';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
explain select * from t1 where a='aaad';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	a	a	8	const	2	Using where
 | 
						|
drop table t1, t2;
 | 
						|
create table t1 (
 | 
						|
id int unsigned not null primary key auto_increment, 
 | 
						|
name varchar(20) not null,
 | 
						|
index heap_idx(name),
 | 
						|
index btree_idx using btree(name)
 | 
						|
) engine=heap;
 | 
						|
create table t2 (
 | 
						|
id int unsigned not null primary key auto_increment, 
 | 
						|
name varchar(20) not null,
 | 
						|
index btree_idx using btree(name),
 | 
						|
index heap_idx(name)
 | 
						|
) engine=heap;
 | 
						|
insert into t1 (name) values ('Matt'), ('Lilu'), ('Corbin'), ('Carly'), 
 | 
						|
('Suzy'), ('Hoppy'), ('Burrito'), ('Mimi'), ('Sherry'), ('Ben'), ('Phil'), 
 | 
						|
('Emily'), ('Mike');
 | 
						|
insert into t2 select * from t1;
 | 
						|
explain select * from t1 where name='matt';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	heap_idx,btree_idx	heap_idx	22	const	1	Using where
 | 
						|
explain select * from t2 where name='matt';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t2	ref	btree_idx,heap_idx	btree_idx	22	const	1	Using where
 | 
						|
explain select * from t1 where name='Lilu';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	heap_idx,btree_idx	heap_idx	22	const	1	Using where
 | 
						|
explain select * from t2 where name='Lilu';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t2	ref	btree_idx,heap_idx	btree_idx	22	const	1	Using where
 | 
						|
explain select * from t1 where name='Phil';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	heap_idx,btree_idx	heap_idx	22	const	1	Using where
 | 
						|
explain select * from t2 where name='Phil';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t2	ref	btree_idx,heap_idx	btree_idx	22	const	1	Using where
 | 
						|
explain select * from t1 where name='Lilu';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	heap_idx,btree_idx	heap_idx	22	const	1	Using where
 | 
						|
explain select * from t2 where name='Lilu';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t2	ref	btree_idx,heap_idx	btree_idx	22	const	1	Using where
 | 
						|
insert into t1 (name) select name from t2;
 | 
						|
insert into t1 (name) select name from t2;
 | 
						|
insert into t1 (name) select name from t2;
 | 
						|
insert into t1 (name) select name from t2;
 | 
						|
insert into t1 (name) select name from t2;
 | 
						|
insert into t1 (name) select name from t2;
 | 
						|
flush tables;
 | 
						|
select count(*) from t1 where name='Matt';
 | 
						|
count(*)
 | 
						|
7
 | 
						|
explain select * from t1 ignore index (btree_idx) where name='matt';
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	heap_idx	heap_idx	22	const	7	Using where
 | 
						|
show index from t1;
 | 
						|
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 | 
						|
t1	0	PRIMARY	1	id	NULL	91	NULL	NULL		HASH	
 | 
						|
t1	1	heap_idx	1	name	NULL	13	NULL	NULL		HASH	
 | 
						|
t1	1	btree_idx	1	name	A	NULL	NULL	NULL		BTREE	
 | 
						|
show index from t1;
 | 
						|
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 | 
						|
t1	0	PRIMARY	1	id	NULL	91	NULL	NULL		HASH	
 | 
						|
t1	1	heap_idx	1	name	NULL	13	NULL	NULL		HASH	
 | 
						|
t1	1	btree_idx	1	name	A	NULL	NULL	NULL		BTREE	
 | 
						|
create table t3
 | 
						|
(
 | 
						|
a varchar(20) not null,
 | 
						|
b varchar(20) not null,
 | 
						|
key (a,b)
 | 
						|
) engine=heap;
 | 
						|
insert into t3 select name, name from t1;
 | 
						|
show index from t3;
 | 
						|
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 | 
						|
t3	1	a	1	a	NULL	NULL	NULL	NULL		HASH	
 | 
						|
t3	1	a	2	b	NULL	13	NULL	NULL		HASH	
 | 
						|
show index from t3;
 | 
						|
Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
 | 
						|
t3	1	a	1	a	NULL	NULL	NULL	NULL		HASH	
 | 
						|
t3	1	a	2	b	NULL	13	NULL	NULL		HASH	
 | 
						|
explain select * from t1 ignore key(btree_idx), t3 where t1.name='matt' and t3.a = concat('',t1.name) and t3.b=t1.name;
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	ref	heap_idx	heap_idx	22	const	7	Using where
 | 
						|
1	SIMPLE	t3	ref	a	a	44	const,const	7	Using where
 | 
						|
drop table t1, t2, t3;
 | 
						|
create temporary table t1 ( a int, index (a) ) engine=memory;
 | 
						|
insert into t1 values (1),(2),(3),(4),(5);
 | 
						|
select a from t1 where a in (1,3);
 | 
						|
a
 | 
						|
1
 | 
						|
3
 | 
						|
explain select a from t1 where a in (1,3);
 | 
						|
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 | 
						|
1	SIMPLE	t1	range	a	a	5	NULL	2	Using where
 | 
						|
drop table t1;
 |