drop table if exists t1; create table t1 (a int not null,b int not null, primary key using BTREE (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 Index_comment Ignored t1 0 PRIMARY 1 a A NULL NULL NULL BTREE NO 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 BTREE (c,a); drop table t1; create table t1 (a int not null,b int not null, primary key using BTREE (a)) engine=heap comment="testing heaps"; insert into t1 values(-2,-2),(-1,-1),(0,0),(1,1),(2,2),(3,3),(4,4); delete from t1 where a > -3; select * from t1; a b drop table t1; create table t1 (a int not null,b int not null, primary key using BTREE (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 BTREE (a); select * from t1 where a > 736494; a 802616 869751 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 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 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 BTREE (x,y), unique y using BTREE (y)) engine=heap; insert into t1 values (1,1),(2,2),(1,3),(2,4),(2,5),(2,6); explain select * from t1 where x=1; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 ref x x 4 const 1 select * from t1 where x=1; x y 1 1 1 3 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 BTREE (a,b), key using BTREE (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 1 1 2 1 3 1 4 1 5 1 6 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 1 1 1 1 2 1 2 1 3 1 3 1 4 1 4 1 5 1 5 1 6 1 6 explain select * from tx where a=x order by a,b; id select_type table type possible_keys key key_len ref rows Extra x SIMPLE tx ref a a x const x Using where explain select * from tx where a=x order by b; id select_type table type possible_keys key key_len ref rows Extra x SIMPLE tx ref a a x const x Using where select * from t1 where b=1; a b 1 1 1 1 explain select * from tx where b=x; id select_type table type possible_keys key key_len ref rows Extra x SIMPLE tx ref b b x const x drop table t1; create table t1 (id int unsigned not null, primary key using BTREE (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 BTREE (btn)) engine=heap; insert into t1 values ("hello"),("hello"),("hello"),("hello"),("hello"),("hello"),("hello"), ("a"),("b"),("c"),("d"),("e"),("f"),("g"),("h"),("i"); explain select * from t1 where btn like "i%"; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range btn btn 10 NULL 1 Using where explain select * from t1 where btn like "h%"; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range btn btn 10 NULL # Using where explain select * from t1 where btn like "a%"; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range btn btn 10 NULL 1 Using where explain select * from t1 where btn like "b%"; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range btn btn 10 NULL 1 Using where select * from t1 where btn like "ff%"; btn select * from t1 where btn like " %"; btn select * from t1 where btn like "q%"; btn alter table t1 add column new_col char(1) not null, add key using BTREE (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 ref btn btn 10 const 1 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 BTREE (a), UNIQUE b using BTREE (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 'b' DROP TABLE t1; CREATE TABLE t1 (a int, b int, c int, key using BTREE (a, b, c)) engine=heap; INSERT INTO t1 VALUES (1, NULL, NULL), (1, 1, NULL), (1, NULL, 1); SELECT * FROM t1 WHERE a=1 and b IS NULL; a b c 1 NULL NULL 1 NULL 1 SELECT * FROM t1 WHERE a=1 and c IS NULL; a b c 1 NULL NULL 1 1 NULL SELECT * FROM t1 WHERE a=1 and b IS NULL and c IS NULL; a b c 1 NULL NULL DROP TABLE t1; CREATE TABLE t1 (a int not null, primary key using BTREE (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 int not null, key using btree(a)) engine=heap; insert into t1 values (2), (2), (2), (1), (1), (3), (3), (3), (3); select a from t1 where a > 2 order by a; a 3 3 3 3 delete from t1 where a < 4; select a from t1 order by a; a insert into t1 values (2), (2), (2), (1), (1), (3), (3), (3), (3); select a from t1 where a > 4 order by a; a delete from t1 where a > 4; select a from t1 order by a; a 1 1 2 2 2 3 3 3 3 select a from t1 where a > 3 order by a; a delete from t1 where a >= 2; select a from t1 order by a; a 1 1 drop table t1; CREATE TABLE t1 ( c1 CHAR(3), c2 INTEGER, KEY USING BTREE(c1), KEY USING BTREE(c2) ) ENGINE= MEMORY; INSERT INTO t1 VALUES ('ABC',0), ('A',0), ('B',0), ('C',0); UPDATE t1 SET c2= c2 + 1 WHERE c1 = 'A'; SELECT * FROM t1; c1 c2 ABC 0 A 1 B 0 C 0 DROP TABLE t1; CREATE TABLE t1 ( c1 ENUM('1', '2'), UNIQUE USING BTREE(c1) ) ENGINE= MEMORY DEFAULT CHARSET= utf8; INSERT INTO t1 VALUES('1'), ('2'); DROP TABLE t1; CREATE TABLE t1 ( c1 SET('1', '2'), UNIQUE USING BTREE(c1) ) ENGINE= MEMORY DEFAULT CHARSET= utf8; INSERT INTO t1 VALUES('1'), ('2'); DROP TABLE t1; CREATE TABLE t1 (a INT, KEY USING BTREE(a)) ENGINE=MEMORY; INSERT INTO t1 VALUES(1),(2),(2); DELETE FROM t1 WHERE a=2; SELECT * FROM t1; a 1 DROP TABLE t1; End of 4.1 tests CREATE TABLE t1(val INT, KEY USING BTREE(val)) ENGINE=memory; INSERT INTO t1 VALUES(0); SELECT INDEX_LENGTH FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='t1'; INDEX_LENGTH 21 UPDATE t1 SET val=1; SELECT INDEX_LENGTH FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME='t1'; INDEX_LENGTH 21 DROP TABLE t1; CREATE TABLE t1 (a INT, UNIQUE USING BTREE(a)) ENGINE=MEMORY; INSERT INTO t1 VALUES(NULL),(NULL); DROP TABLE t1; create table t1(a varchar(255), b varchar(255), key using btree (a,b)) engine=memory; insert into t1 values (1, 1), (3, 3), (2, 2), (NULL, 1), (NULL, NULL), (0, 0); select * from t1 where a is null; a b NULL NULL NULL 1 drop table t1; # # bug#39918 - memory (heap) engine crashing while executing self join with delete # CREATE TABLE t1(a INT, KEY USING BTREE (a)) ENGINE=MEMORY; INSERT INTO t1 VALUES(1),(1); DELETE a1 FROM t1 AS a1, t1 AS a2 WHERE a1.a=a2.a; DROP TABLE t1; End of 5.0 tests # bit index in heap tables create table t1 (a bit(63) not null) engine=heap; insert into t1 values (869751),(736494),(226312),(802616),(728912); alter table t1 add unique uniq_id using BTREE (a); select 0+a from t1 where a > 736494; 0+a 802616 869751 explain select 0+a from t1 where a > 736494; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uniq_id uniq_id 8 NULL 3 Using where select 0+a from t1 where a = 736494; 0+a 736494 explain select 0+a from t1 where a = 736494; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 const uniq_id uniq_id 8 const 1 select 0+a from t1 where a=869751 or a=736494; 0+a 736494 869751 explain select 0+a from t1 where a=869751 or a=736494; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range uniq_id uniq_id 8 NULL 2 Using where insert into t1 (a) select * from seq_1_to_100; select 0+a from t1 where a in (869751,736494,226312,802616); 0+a 226312 736494 802616 869751 explain select 0+a 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 8 NULL 4 Using where drop table t1; End of 5.3 tests create table t1 (id int, a varchar(300) not null, key using btree(a)) engine=heap; insert t1 values (1, repeat('a', 300)); drop table t1; End of 5.5 tests