drop table if exists t1, t2; # # Bug#48229: group by performance issue of partitioned table # CREATE TABLE t1 ( a INT, b INT, KEY a (a,b) ) PARTITION BY HASH (a) PARTITIONS 1; INSERT INTO t1 VALUES (0, 580092), (3, 894076), (4, 805483), (4, 913540), (6, 611137), (8, 171602), (9, 599495), (9, 746305), (10, 272829), (10, 847519), (12, 258869), (12, 929028), (13, 288970), (15, 20971), (15, 105839), (16, 788272), (17, 76914), (18, 827274), (19, 802258), (20, 123677), (20, 587729), (22, 701449), (25, 31565), (25, 230782), (25, 442887), (25, 733139), (25, 851020); EXPLAIN SELECT a, MAX(b) FROM t1 WHERE a IN (10, 100, 3) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 4 Using where; Using index DROP TABLE t1; create table t1 (a DATETIME) partition by range (TO_DAYS(a)) subpartition by hash(to_seconds(a)) (partition p0 values less than (1)); show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` datetime DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50500 PARTITION BY RANGE (TO_DAYS(a)) SUBPARTITION BY HASH (to_seconds(a)) (PARTITION p0 VALUES LESS THAN (1) ENGINE = MyISAM) */ drop table t1; create table t1 (a int) partition by range (a) ( partition p0 values less than (NULL), partition p1 values less than (MAXVALUE)); ERROR HY000: Not allowed to use NULL value in VALUES LESS THAN create table t1 (a datetime not null) partition by range (TO_SECONDS(a)) ( partition p0 VALUES LESS THAN (TO_SECONDS('2007-03-08 00:00:00')), partition p1 VALUES LESS THAN (TO_SECONDS('2007-04-01 00:00:00'))); select partition_method, partition_expression, partition_description from information_schema.partitions where table_name = "t1"; partition_method partition_expression partition_description RANGE TO_SECONDS(a) 63340531200 RANGE TO_SECONDS(a) 63342604800 INSERT INTO t1 VALUES ('2007-03-01 12:00:00'), ('2007-03-07 12:00:00'); INSERT INTO t1 VALUES ('2007-03-08 12:00:00'), ('2007-03-15 12:00:00'); explain partitions select * from t1 where a < '2007-03-08 00:00:00'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0 ALL NULL NULL NULL NULL 2 Using where explain partitions select * from t1 where a < '2007-03-08 00:00:01'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0,p1 ALL NULL NULL NULL NULL 4 Using where explain partitions select * from t1 where a <= '2007-03-08 00:00:00'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0,p1 ALL NULL NULL NULL NULL 4 Using where explain partitions select * from t1 where a <= '2007-03-07 23:59:59'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0 ALL NULL NULL NULL NULL 2 Using where explain partitions select * from t1 where a < '2007-03-07 23:59:59'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0 ALL NULL NULL NULL NULL 2 Using where show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` datetime NOT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50500 PARTITION BY RANGE (TO_SECONDS(a)) (PARTITION p0 VALUES LESS THAN (63340531200) ENGINE = MyISAM, PARTITION p1 VALUES LESS THAN (63342604800) ENGINE = MyISAM) */ drop table t1; create table t1 (a date) partition by range(to_seconds(a)) (partition p0 values less than (to_seconds('2004-01-01')), partition p1 values less than (to_seconds('2005-01-01'))); insert into t1 values ('2003-12-30'),('2004-12-31'); select * from t1; a 2003-12-30 2004-12-31 explain partitions select * from t1 where a <= '2003-12-31'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0 system NULL NULL NULL NULL 1 select * from t1 where a <= '2003-12-31'; a 2003-12-30 explain partitions select * from t1 where a <= '2005-01-01'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0,p1 ALL NULL NULL NULL NULL 2 Using where select * from t1 where a <= '2005-01-01'; a 2003-12-30 2004-12-31 show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` date DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50500 PARTITION BY RANGE (to_seconds(a)) (PARTITION p0 VALUES LESS THAN (63240134400) ENGINE = MyISAM, PARTITION p1 VALUES LESS THAN (63271756800) ENGINE = MyISAM) */ drop table t1; create table t1 (a datetime) partition by range(to_seconds(a)) (partition p0 values less than (to_seconds('2004-01-01 12:00:00')), partition p1 values less than (to_seconds('2005-01-01 12:00:00'))); insert into t1 values ('2004-01-01 11:59:29'),('2005-01-01 11:59:59'); select * from t1; a 2004-01-01 11:59:29 2005-01-01 11:59:59 explain partitions select * from t1 where a <= '2004-01-01 11:59.59'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0 system NULL NULL NULL NULL 1 select * from t1 where a <= '2004-01-01 11:59:59'; a 2004-01-01 11:59:29 explain partitions select * from t1 where a <= '2005-01-01'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0,p1 ALL NULL NULL NULL NULL 2 Using where select * from t1 where a <= '2005-01-01'; a 2004-01-01 11:59:29 show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` datetime DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50500 PARTITION BY RANGE (to_seconds(a)) (PARTITION p0 VALUES LESS THAN (63240177600) ENGINE = MyISAM, PARTITION p1 VALUES LESS THAN (63271800000) ENGINE = MyISAM) */ drop table t1; create table t1 (a int, b char(20)) partition by range columns(a,b) (partition p0 values less than (1)); ERROR 42000: Inconsistency in usage of column lists for partitioning near '))' at line 3 create table t1 (a int, b char(20)) partition by range(a) (partition p0 values less than (1,"b")); ERROR HY000: Cannot have more than one value for this type of RANGE partitioning create table t1 (a int, b char(20)) partition by range(a) (partition p0 values less than (1,"b")); ERROR HY000: Cannot have more than one value for this type of RANGE partitioning create table t1 (a int, b char(20)) partition by range columns(b) (partition p0 values less than ("b")); drop table t1; create table t1 (a int) partition by range (a) ( partition p0 values less than (maxvalue)); alter table t1 add partition (partition p1 values less than (100000)); ERROR HY000: MAXVALUE can only be used in last partition definition show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN MAXVALUE ENGINE = MyISAM) */ drop table t1; create table t1 (a integer) partition by range (a) ( partition p0 values less than (4), partition p1 values less than (100)); create trigger tr1 before insert on t1 for each row begin set @a = 1; end| alter table t1 drop partition p0; drop table t1; create table t1 (a integer) partition by range (a) ( partition p0 values less than (4), partition p1 values less than (100)); LOCK TABLES t1 WRITE; alter table t1 drop partition p0; alter table t1 reorganize partition p1 into ( partition p0 values less than (4), partition p1 values less than (100)); alter table t1 add partition ( partition p2 values less than (200)); UNLOCK TABLES; drop table t1; create table t1 (a int unsigned) partition by range (a) (partition pnull values less than (0), partition p0 values less than (1), partition p1 values less than(2)); insert into t1 values (null),(0),(1); select * from t1 where a is null; a NULL select * from t1 where a >= 0; a 0 1 select * from t1 where a < 0; a select * from t1 where a <= 0; a 0 select * from t1 where a > 1; a explain partitions select * from t1 where a is null; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 pnull system NULL NULL NULL NULL 1 explain partitions select * from t1 where a >= 0; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0,p1 ALL NULL NULL NULL NULL 2 Using where explain partitions select * from t1 where a < 0; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables explain partitions select * from t1 where a <= 0; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 pnull,p0 ALL NULL NULL NULL NULL 2 Using where explain partitions select * from t1 where a > 1; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables drop table t1; create table t1 (a int unsigned, b int unsigned) partition by range (a) subpartition by hash (b) subpartitions 2 (partition pnull values less than (0), partition p0 values less than (1), partition p1 values less than(2)); insert into t1 values (null,0),(null,1),(0,0),(0,1),(1,0),(1,1); select * from t1 where a is null; a b NULL 0 NULL 1 select * from t1 where a >= 0; a b 0 0 0 1 1 0 1 1 select * from t1 where a < 0; a b select * from t1 where a <= 0; a b 0 0 0 1 select * from t1 where a > 1; a b explain partitions select * from t1 where a is null; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 pnull_pnullsp0,pnull_pnullsp1 ALL NULL NULL NULL NULL 2 Using where explain partitions select * from t1 where a >= 0; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p0_p0sp0,p0_p0sp1,p1_p1sp0,p1_p1sp1 ALL NULL NULL NULL NULL 4 Using where explain partitions select * from t1 where a < 0; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 pnull_pnullsp0,pnull_pnullsp1 ALL NULL NULL NULL NULL 2 Using where explain partitions select * from t1 where a <= 0; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 pnull_pnullsp0,pnull_pnullsp1,p0_p0sp0,p0_p0sp1 ALL NULL NULL NULL NULL 4 Using where explain partitions select * from t1 where a > 1; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key(a,b)) partition by range (a) partitions 3 (partition x1 values less than (5) tablespace ts1, partition x2 values less than (10) tablespace ts2, partition x3 values less than maxvalue tablespace ts3); INSERT into t1 values (1, 1, 1); INSERT into t1 values (6, 1, 1); INSERT into t1 values (10, 1, 1); INSERT into t1 values (15, 1, 1); select * from t1; a b c 1 1 1 6 1 1 10 1 1 15 1 1 show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) NOT NULL, `b` int(11) NOT NULL, `c` int(11) NOT NULL, PRIMARY KEY (`a`,`b`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) (PARTITION x1 VALUES LESS THAN (5) TABLESPACE = ts1 ENGINE = MyISAM, PARTITION x2 VALUES LESS THAN (10) TABLESPACE = ts2 ENGINE = MyISAM, PARTITION x3 VALUES LESS THAN MAXVALUE TABLESPACE = ts3 ENGINE = MyISAM) */ ALTER TABLE t1 partition by range (a) partitions 3 (partition x1 values less than (5) tablespace ts1, partition x2 values less than (10) tablespace ts2, partition x3 values less than maxvalue tablespace ts3); select * from t1; a b c 1 1 1 6 1 1 10 1 1 15 1 1 show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) NOT NULL, `b` int(11) NOT NULL, `c` int(11) NOT NULL, PRIMARY KEY (`a`,`b`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) (PARTITION x1 VALUES LESS THAN (5) TABLESPACE = ts1 ENGINE = MyISAM, PARTITION x2 VALUES LESS THAN (10) TABLESPACE = ts2 ENGINE = MyISAM, PARTITION x3 VALUES LESS THAN MAXVALUE TABLESPACE = ts3 ENGINE = MyISAM) */ drop table if exists t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null) partition by range (a) partitions 3 (partition x1 values less than (5) tablespace ts1, partition x2 values less than (10) tablespace ts2, partition x3 values less than maxvalue tablespace ts3); INSERT into t1 values (1, 1, 1); INSERT into t1 values (6, 1, 1); INSERT into t1 values (10, 1, 1); INSERT into t1 values (15, 1, 1); select * from t1; a b c 1 1 1 6 1 1 10 1 1 15 1 1 ALTER TABLE t1 partition by range (a) partitions 3 (partition x1 values less than (5) tablespace ts1, partition x2 values less than (10) tablespace ts2, partition x3 values less than maxvalue tablespace ts3); select * from t1; a b c 1 1 1 6 1 1 10 1 1 15 1 1 drop table if exists t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key(a,b)) partition by range (a) partitions 3 (partition x1 values less than (5) tablespace ts1, partition x2 values less than (10) tablespace ts2, partition x3 values less than (15) tablespace ts3); INSERT into t1 values (1, 1, 1); INSERT into t1 values (6, 1, 1); INSERT into t1 values (10, 1, 1); INSERT into t1 values (15, 1, 1); ERROR HY000: Table has no partition for value 15 select * from t1; a b c 1 1 1 6 1 1 10 1 1 ALTER TABLE t1 partition by range (a) partitions 3 (partition x1 values less than (5) tablespace ts1, partition x2 values less than (10) tablespace ts2, partition x3 values less than (15) tablespace ts3); select * from t1; a b c 1 1 1 6 1 1 10 1 1 drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key(a,b)) partition by range (a) (partition x1 values less than (1)); drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11, subpartition x12), partition x2 values less than (5) ( subpartition x21, subpartition x22) ); SELECT * from t1; a b c show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) NOT NULL, `b` int(11) NOT NULL, `c` int(11) NOT NULL, PRIMARY KEY (`a`,`b`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) SUBPARTITION BY HASH (a+b) (PARTITION x1 VALUES LESS THAN (1) (SUBPARTITION x11 ENGINE = MyISAM, SUBPARTITION x12 ENGINE = MyISAM), PARTITION x2 VALUES LESS THAN (5) (SUBPARTITION x21 ENGINE = MyISAM, SUBPARTITION x22 ENGINE = MyISAM)) */ ALTER TABLE t1 ADD COLUMN d int; show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) NOT NULL, `b` int(11) NOT NULL, `c` int(11) NOT NULL, `d` int(11) DEFAULT NULL, PRIMARY KEY (`a`,`b`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) SUBPARTITION BY HASH (a+b) (PARTITION x1 VALUES LESS THAN (1) (SUBPARTITION x11 ENGINE = MyISAM, SUBPARTITION x12 ENGINE = MyISAM), PARTITION x2 VALUES LESS THAN (5) (SUBPARTITION x21 ENGINE = MyISAM, SUBPARTITION x22 ENGINE = MyISAM)) */ drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 tablespace t1 engine myisam nodegroup 0, subpartition x12 tablespace t2 engine myisam nodegroup 1), partition x2 values less than (5) ( subpartition x21 tablespace t1 engine myisam nodegroup 0, subpartition x22 tablespace t2 engine myisam nodegroup 1) ); SELECT * from t1; a b c drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 tablespace t1 nodegroup 0, subpartition x12 tablespace t2 nodegroup 1), partition x2 values less than (5) ( subpartition x21 tablespace t1 nodegroup 0, subpartition x22 tablespace t2 nodegroup 1) ); SELECT * from t1; a b c drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 engine myisam nodegroup 0, subpartition x12 engine myisam nodegroup 1), partition x2 values less than (5) ( subpartition x21 engine myisam nodegroup 0, subpartition x22 engine myisam nodegroup 1) ); INSERT into t1 VALUES (1,1,1); INSERT into t1 VALUES (4,1,1); INSERT into t1 VALUES (5,1,1); ERROR HY000: Table has no partition for value 5 SELECT * from t1; a b c 1 1 1 4 1 1 ALTER TABLE t1 partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 engine myisam nodegroup 0, subpartition x12 engine myisam nodegroup 1), partition x2 values less than (5) ( subpartition x21 engine myisam nodegroup 0, subpartition x22 engine myisam nodegroup 1) ); SELECT * from t1; a b c 1 1 1 4 1 1 drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 tablespace t1 engine myisam, subpartition x12 tablespace t2 engine myisam), partition x2 values less than (5) ( subpartition x21 tablespace t1 engine myisam, subpartition x22 tablespace t2 engine myisam) ); INSERT into t1 VALUES (1,1,1); INSERT into t1 VALUES (4,1,1); INSERT into t1 VALUES (5,1,1); ERROR HY000: Table has no partition for value 5 SELECT * from t1; a b c 1 1 1 4 1 1 ALTER TABLE t1 partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 tablespace t1 engine myisam, subpartition x12 tablespace t2 engine myisam), partition x2 values less than (5) ( subpartition x21 tablespace t1 engine myisam, subpartition x22 tablespace t2 engine myisam) ); SELECT * from t1; a b c 1 1 1 4 1 1 drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 tablespace t1, subpartition x12 tablespace t2), partition x2 values less than (5) ( subpartition x21 tablespace t1, subpartition x22 tablespace t2) ); INSERT into t1 VALUES (1,1,1); INSERT into t1 VALUES (4,1,1); INSERT into t1 VALUES (5,1,1); ERROR HY000: Table has no partition for value 5 SELECT * from t1; a b c 1 1 1 4 1 1 ALTER TABLE t1 partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 tablespace t1 engine myisam, subpartition x12 tablespace t2 engine myisam), partition x2 values less than (5) ( subpartition x21 tablespace t1 engine myisam, subpartition x22 tablespace t2 engine myisam) ); SELECT * from t1; a b c 1 1 1 4 1 1 drop table t1; CREATE TABLE t1 ( a int not null, b int not null, c int not null, primary key (a,b)) partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 engine myisam, subpartition x12 engine myisam), partition x2 values less than (5) ( subpartition x21 engine myisam, subpartition x22 engine myisam) ); INSERT into t1 VALUES (1,1,1); INSERT into t1 VALUES (4,1,1); INSERT into t1 VALUES (5,1,1); ERROR HY000: Table has no partition for value 5 SELECT * from t1; a b c 1 1 1 4 1 1 ALTER TABLE t1 partition by range (a) subpartition by hash (a+b) ( partition x1 values less than (1) ( subpartition x11 engine myisam, subpartition x12 engine myisam), partition x2 values less than (5) ( subpartition x21 engine myisam, subpartition x22 engine myisam) ); SELECT * from t1; a b c 1 1 1 4 1 1 drop table t1; CREATE TABLE t1 (c1 int default NULL, c2 varchar(30) default NULL, c3 date default NULL) engine=myisam PARTITION BY RANGE (year(c3)) (PARTITION p0 VALUES LESS THAN (1995), PARTITION p1 VALUES LESS THAN (1996) , PARTITION p2 VALUES LESS THAN (1997) , PARTITION p3 VALUES LESS THAN (1998) , PARTITION p4 VALUES LESS THAN (1999) , PARTITION p5 VALUES LESS THAN (2000) , PARTITION p6 VALUES LESS THAN (2001) , PARTITION p7 VALUES LESS THAN (2002) , PARTITION p8 VALUES LESS THAN (2003) , PARTITION p9 VALUES LESS THAN (2004) , PARTITION p10 VALUES LESS THAN (2010), PARTITION p11 VALUES LESS THAN MAXVALUE ); INSERT INTO t1 VALUES (1, 'testing partitions', '1995-07-17'), (3, 'testing partitions','1995-07-31'), (5, 'testing partitions','1995-08-13'), (7, 'testing partitions','1995-08-26'), (9, 'testing partitions','1995-09-09'), (0, 'testing partitions','2000-07-10'), (2, 'testing partitions','2000-07-23'), (4, 'testing partitions','2000-08-05'), (6, 'testing partitions','2000-08-19'), (8, 'testing partitions','2000-09-01'); SELECT COUNT(*) FROM t1 WHERE c3 BETWEEN '1996-12-31' AND '2000-12-31'; COUNT(*) 5 SELECT COUNT(*) FROM t1 WHERE c3 < '2000-12-31'; COUNT(*) 10 DROP TABLE t1; create table t1 (a bigint unsigned) partition by range (a) (partition p0 values less than (10), partition p1 values less than (0)); ERROR HY000: VALUES LESS THAN value must be strictly increasing for each partition create table t1 (a bigint unsigned) partition by range (a) (partition p0 values less than (0), partition p1 values less than (10)); show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` bigint(20) unsigned DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (0) ENGINE = MyISAM, PARTITION p1 VALUES LESS THAN (10) ENGINE = MyISAM) */ drop table t1; create table t1 (a bigint unsigned) partition by range (a) (partition p0 values less than (2), partition p1 values less than (10)); show create table t1; Table Create Table t1 CREATE TABLE `t1` ( `a` bigint(20) unsigned DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 /*!50100 PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (2) ENGINE = MyISAM, PARTITION p1 VALUES LESS THAN (10) ENGINE = MyISAM) */ insert into t1 values (0xFFFFFFFFFFFFFFFF); ERROR HY000: Table has no partition for value 18446744073709551615 drop table t1; create table t1 (a int) partition by range (MOD(a,3)) subpartition by hash(a) subpartitions 2 (partition p0 values less than (1), partition p1 values less than (2), partition p2 values less than (3), partition p3 values less than (4)); ALTER TABLE t1 DROP PARTITION p3; ALTER TABLE t1 DROP PARTITION p1; ALTER TABLE t1 DROP PARTITION p2; drop table t1; create table t1 (a int) partition by range (MOD(a,3)) subpartition by hash(a) subpartitions 2 (partition p0 values less than (1), partition p1 values less than (2), partition p2 values less than (3), partition p3 values less than (4)); ALTER TABLE t1 DROP PARTITION p0; ALTER TABLE t1 DROP PARTITION p1; ALTER TABLE t1 DROP PARTITION p2; drop table t1; create table t1 (a int DEFAULT NULL, b varchar(30) DEFAULT NULL, c date DEFAULT NULL) ENGINE=MYISAM DEFAULT CHARSET=latin1; insert into t1 values (1, 'abc', '1995-01-01'); insert into t1 values (1, 'abc', '1995-01-02'); insert into t1 values (1, 'abc', '1995-01-03'); insert into t1 values (1, 'abc', '1995-01-04'); insert into t1 values (1, 'abc', '1995-01-05'); insert into t1 values (1, 'abc', '1995-01-06'); insert into t1 values (1, 'abc', '1995-01-07'); insert into t1 values (1, 'abc', '1995-01-08'); insert into t1 values (1, 'abc', '1995-01-09'); insert into t1 values (1, 'abc', '1995-01-10'); insert into t1 values (1, 'abc', '1995-01-11'); insert into t1 values (1, 'abc', '1995-01-12'); insert into t1 values (1, 'abc', '1995-01-13'); insert into t1 values (1, 'abc', '1995-01-14'); insert into t1 values (1, 'abc', '1995-01-15'); insert into t1 values (1, 'abc', '1997-01-01'); insert into t1 values (1, 'abc', '1997-01-02'); insert into t1 values (1, 'abc', '1997-01-03'); insert into t1 values (1, 'abc', '1997-01-04'); insert into t1 values (1, 'abc', '1997-01-05'); insert into t1 values (1, 'abc', '1997-01-06'); insert into t1 values (1, 'abc', '1997-01-07'); insert into t1 values (1, 'abc', '1997-01-08'); insert into t1 values (1, 'abc', '1997-01-09'); insert into t1 values (1, 'abc', '1997-01-10'); insert into t1 values (1, 'abc', '1997-01-11'); insert into t1 values (1, 'abc', '1997-01-12'); insert into t1 values (1, 'abc', '1997-01-13'); insert into t1 values (1, 'abc', '1997-01-14'); insert into t1 values (1, 'abc', '1997-01-15'); insert into t1 values (1, 'abc', '1998-01-01'); insert into t1 values (1, 'abc', '1998-01-02'); insert into t1 values (1, 'abc', '1998-01-03'); insert into t1 values (1, 'abc', '1998-01-04'); insert into t1 values (1, 'abc', '1998-01-05'); insert into t1 values (1, 'abc', '1998-01-06'); insert into t1 values (1, 'abc', '1998-01-07'); insert into t1 values (1, 'abc', '1998-01-08'); insert into t1 values (1, 'abc', '1998-01-09'); insert into t1 values (1, 'abc', '1998-01-10'); insert into t1 values (1, 'abc', '1998-01-11'); insert into t1 values (1, 'abc', '1998-01-12'); insert into t1 values (1, 'abc', '1998-01-13'); insert into t1 values (1, 'abc', '1998-01-14'); insert into t1 values (1, 'abc', '1998-01-15'); insert into t1 values (1, 'abc', '1999-01-01'); insert into t1 values (1, 'abc', '1999-01-02'); insert into t1 values (1, 'abc', '1999-01-03'); insert into t1 values (1, 'abc', '1999-01-04'); insert into t1 values (1, 'abc', '1999-01-05'); insert into t1 values (1, 'abc', '1999-01-06'); insert into t1 values (1, 'abc', '1999-01-07'); insert into t1 values (1, 'abc', '1999-01-08'); insert into t1 values (1, 'abc', '1999-01-09'); insert into t1 values (1, 'abc', '1999-01-10'); insert into t1 values (1, 'abc', '1999-01-11'); insert into t1 values (1, 'abc', '1999-01-12'); insert into t1 values (1, 'abc', '1999-01-13'); insert into t1 values (1, 'abc', '1999-01-14'); insert into t1 values (1, 'abc', '1999-01-15'); insert into t1 values (1, 'abc', '2000-01-01'); insert into t1 values (1, 'abc', '2000-01-02'); insert into t1 values (1, 'abc', '2000-01-03'); insert into t1 values (1, 'abc', '2000-01-04'); insert into t1 values (1, 'abc', '2000-01-05'); insert into t1 values (1, 'abc', '2000-01-06'); insert into t1 values (1, 'abc', '2000-01-07'); insert into t1 values (1, 'abc', '2000-01-08'); insert into t1 values (1, 'abc', '2000-01-09'); insert into t1 values (1, 'abc', '2000-01-15'); insert into t1 values (1, 'abc', '2000-01-11'); insert into t1 values (1, 'abc', '2000-01-12'); insert into t1 values (1, 'abc', '2000-01-13'); insert into t1 values (1, 'abc', '2000-01-14'); insert into t1 values (1, 'abc', '2000-01-15'); insert into t1 values (1, 'abc', '2001-01-01'); insert into t1 values (1, 'abc', '2001-01-02'); insert into t1 values (1, 'abc', '2001-01-03'); insert into t1 values (1, 'abc', '2001-01-04'); insert into t1 values (1, 'abc', '2001-01-05'); insert into t1 values (1, 'abc', '2001-01-06'); insert into t1 values (1, 'abc', '2001-01-07'); insert into t1 values (1, 'abc', '2001-01-08'); insert into t1 values (1, 'abc', '2001-01-09'); insert into t1 values (1, 'abc', '2001-01-15'); insert into t1 values (1, 'abc', '2001-01-11'); insert into t1 values (1, 'abc', '2001-01-12'); insert into t1 values (1, 'abc', '2001-01-13'); insert into t1 values (1, 'abc', '2001-01-14'); insert into t1 values (1, 'abc', '2001-01-15'); alter table t1 partition by range (year(c)) (partition p5 values less than (2000), partition p10 values less than (2010)); alter table t1 reorganize partition p5 into (partition p1 values less than (1996), partition p2 values less than (1997), partition p3 values less than (1998), partition p4 values less than (1999), partition p5 values less than (2000)); drop table t1; CREATE TABLE t1 (a date) PARTITION BY RANGE (TO_DAYS(a)) (PARTITION p3xx VALUES LESS THAN (TO_DAYS('2004-01-01')), PARTITION p401 VALUES LESS THAN (TO_DAYS('2004-02-01')), PARTITION p402 VALUES LESS THAN (TO_DAYS('2004-03-01')), PARTITION p403 VALUES LESS THAN (TO_DAYS('2004-04-01')), PARTITION p404 VALUES LESS THAN (TO_DAYS('2004-05-01')), PARTITION p405 VALUES LESS THAN (TO_DAYS('2004-06-01')), PARTITION p406 VALUES LESS THAN (TO_DAYS('2004-07-01')), PARTITION p407 VALUES LESS THAN (TO_DAYS('2004-08-01')), PARTITION p408 VALUES LESS THAN (TO_DAYS('2004-09-01')), PARTITION p409 VALUES LESS THAN (TO_DAYS('2004-10-01')), PARTITION p410 VALUES LESS THAN (TO_DAYS('2004-11-01')), PARTITION p411 VALUES LESS THAN (TO_DAYS('2004-12-01')), PARTITION p412 VALUES LESS THAN (TO_DAYS('2005-01-01')), PARTITION p501 VALUES LESS THAN (TO_DAYS('2005-02-01')), PARTITION p502 VALUES LESS THAN (TO_DAYS('2005-03-01')), PARTITION p503 VALUES LESS THAN (TO_DAYS('2005-04-01')), PARTITION p504 VALUES LESS THAN (TO_DAYS('2005-05-01')), PARTITION p505 VALUES LESS THAN (TO_DAYS('2005-06-01')), PARTITION p506 VALUES LESS THAN (TO_DAYS('2005-07-01')), PARTITION p507 VALUES LESS THAN (TO_DAYS('2005-08-01')), PARTITION p508 VALUES LESS THAN (TO_DAYS('2005-09-01')), PARTITION p509 VALUES LESS THAN (TO_DAYS('2005-10-01')), PARTITION p510 VALUES LESS THAN (TO_DAYS('2005-11-01')), PARTITION p511 VALUES LESS THAN (TO_DAYS('2005-12-01')), PARTITION p512 VALUES LESS THAN (TO_DAYS('2006-01-01')), PARTITION p601 VALUES LESS THAN (TO_DAYS('2006-02-01')), PARTITION p602 VALUES LESS THAN (TO_DAYS('2006-03-01')), PARTITION p603 VALUES LESS THAN (TO_DAYS('2006-04-01')), PARTITION p604 VALUES LESS THAN (TO_DAYS('2006-05-01')), PARTITION p605 VALUES LESS THAN (TO_DAYS('2006-06-01')), PARTITION p606 VALUES LESS THAN (TO_DAYS('2006-07-01')), PARTITION p607 VALUES LESS THAN (TO_DAYS('2006-08-01'))); INSERT INTO t1 VALUES ('2003-01-13'),('2003-06-20'),('2003-08-30'); INSERT INTO t1 VALUES ('2003-04-13'),('2003-07-20'),('2003-10-30'); INSERT INTO t1 VALUES ('2003-05-13'),('2003-11-20'),('2003-12-30'); INSERT INTO t1 VALUES ('2004-01-13'),('2004-01-20'),('2004-01-30'); INSERT INTO t1 VALUES ('2004-02-13'),('2004-02-20'),('2004-02-28'); INSERT INTO t1 VALUES ('2004-03-13'),('2004-03-20'),('2004-03-30'); INSERT INTO t1 VALUES ('2004-04-13'),('2004-04-20'),('2004-04-30'); INSERT INTO t1 VALUES ('2004-05-13'),('2004-05-20'),('2004-05-30'); INSERT INTO t1 VALUES ('2004-06-13'),('2004-06-20'),('2004-06-30'); INSERT INTO t1 VALUES ('2004-07-13'),('2004-07-20'),('2004-07-30'); INSERT INTO t1 VALUES ('2004-08-13'),('2004-08-20'),('2004-08-30'); INSERT INTO t1 VALUES ('2004-09-13'),('2004-09-20'),('2004-09-30'); INSERT INTO t1 VALUES ('2004-10-13'),('2004-10-20'),('2004-10-30'); INSERT INTO t1 VALUES ('2004-11-13'),('2004-11-20'),('2004-11-30'); INSERT INTO t1 VALUES ('2004-12-13'),('2004-12-20'),('2004-12-30'); INSERT INTO t1 VALUES ('2005-01-13'),('2005-01-20'),('2005-01-30'); INSERT INTO t1 VALUES ('2005-02-13'),('2005-02-20'),('2005-02-28'); INSERT INTO t1 VALUES ('2005-03-13'),('2005-03-20'),('2005-03-30'); INSERT INTO t1 VALUES ('2005-04-13'),('2005-04-20'),('2005-04-30'); INSERT INTO t1 VALUES ('2005-05-13'),('2005-05-20'),('2005-05-30'); INSERT INTO t1 VALUES ('2005-06-13'),('2005-06-20'),('2005-06-30'); INSERT INTO t1 VALUES ('2005-07-13'),('2005-07-20'),('2005-07-30'); INSERT INTO t1 VALUES ('2005-08-13'),('2005-08-20'),('2005-08-30'); INSERT INTO t1 VALUES ('2005-09-13'),('2005-09-20'),('2005-09-30'); INSERT INTO t1 VALUES ('2005-10-13'),('2005-10-20'),('2005-10-30'); INSERT INTO t1 VALUES ('2005-11-13'),('2005-11-20'),('2005-11-30'); INSERT INTO t1 VALUES ('2005-12-13'),('2005-12-20'),('2005-12-30'); INSERT INTO t1 VALUES ('2006-01-13'),('2006-01-20'),('2006-01-30'); INSERT INTO t1 VALUES ('2006-02-13'),('2006-02-20'),('2006-02-28'); INSERT INTO t1 VALUES ('2006-03-13'),('2006-03-20'),('2006-03-30'); INSERT INTO t1 VALUES ('2006-04-13'),('2006-04-20'),('2006-04-30'); INSERT INTO t1 VALUES ('2006-05-13'),('2006-05-20'),('2006-05-30'); INSERT INTO t1 VALUES ('2006-06-13'),('2006-06-20'),('2006-06-30'); INSERT INTO t1 VALUES ('2006-07-13'),('2006-07-20'),('2006-07-30'); SELECT * FROM t1 WHERE a >= '2004-07-01' AND a <= '2004-09-30'; a 2004-07-13 2004-07-20 2004-07-30 2004-08-13 2004-08-20 2004-08-30 2004-09-13 2004-09-20 2004-09-30 EXPLAIN PARTITIONS SELECT * FROM t1 WHERE a >= '2004-07-01' AND a <= '2004-09-30'; id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p3xx,p407,p408,p409 ALL NULL NULL NULL NULL 18 Using where SELECT * from t1 WHERE (a >= '2004-07-01' AND a <= '2004-09-30') OR (a >= '2005-07-01' AND a <= '2005-09-30'); a 2004-07-13 2004-07-20 2004-07-30 2004-08-13 2004-08-20 2004-08-30 2004-09-13 2004-09-20 2004-09-30 2005-07-13 2005-07-20 2005-07-30 2005-08-13 2005-08-20 2005-08-30 2005-09-13 2005-09-20 2005-09-30 EXPLAIN PARTITIONS SELECT * from t1 WHERE (a >= '2004-07-01' AND a <= '2004-09-30') OR (a >= '2005-07-01' AND a <= '2005-09-30'); id select_type table partitions type possible_keys key key_len ref rows Extra 1 SIMPLE t1 p3xx,p407,p408,p409,p507,p508,p509 ALL NULL NULL NULL NULL 27 Using where DROP TABLE t1; create table t1 (a int); insert into t1 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); CREATE TABLE t2 ( defid int(10) unsigned NOT NULL, day int(10) unsigned NOT NULL, count int(10) unsigned NOT NULL, filler char(200), KEY (defid,day) ) PARTITION BY RANGE (day) ( PARTITION p7 VALUES LESS THAN (20070401) , PARTITION p8 VALUES LESS THAN (20070501)); insert into t2 select 20, 20070311, 1, 'filler' from t1 A, t1 B; insert into t2 select 20, 20070411, 1, 'filler' from t1 A, t1 B; insert into t2 values(52, 20070321, 123, 'filler') ; insert into t2 values(52, 20070322, 456, 'filler') ; select sum(count) from t2 ch where ch.defid in (50,52) and ch.day between 20070320 and 20070401 group by defid; sum(count) 579 drop table t1, t2; # # Bug#50939: Loose Index Scan unduly relies on engine to remember range # endpoints # CREATE TABLE t1 ( a INT, b INT, KEY ( a, b ) ) PARTITION BY HASH (a) PARTITIONS 1; CREATE TABLE t2 ( a INT, b INT, KEY ( a, b ) ); INSERT INTO t1 VALUES (1, 1), (2, 2), (3, 3), (4, 4), (5, 5); INSERT INTO t1 SELECT a + 5, b + 5 FROM t1; INSERT INTO t1 SELECT a + 10, b + 10 FROM t1; INSERT INTO t1 SELECT a + 20, b + 20 FROM t1; INSERT INTO t1 SELECT a + 40, b + 40 FROM t1; INSERT INTO t2 SELECT * FROM t1; # plans should be identical EXPLAIN SELECT a, MAX(b) FROM t1 WHERE a IN (10,100) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t1 range a a 5 NULL 1 Using where; Using index for group-by EXPLAIN SELECT a, MAX(b) FROM t2 WHERE a IN (10,100) GROUP BY a; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE t2 range a a 5 NULL 2 Using where; Using index for group-by FLUSH status; SELECT a, MAX(b) FROM t1 WHERE a IN (10, 100) GROUP BY a; a MAX(b) 10 10 # Should be no more than 4 reads. SHOW status LIKE 'handler_read_key'; Variable_name Value Handler_read_key 4 FLUSH status; SELECT a, MAX(b) FROM t2 WHERE a IN (10, 100) GROUP BY a; a MAX(b) 10 10 # Should be no more than 4 reads. SHOW status LIKE 'handler_read_key'; Variable_name Value Handler_read_key 4 DROP TABLE t1, t2;