set @save_optimizer_switch=@@optimizer_switch; ------------------------------- Part 1: Feature tests. ------------------------------- Default for all tests. set @@optimizer_switch = "materialization=on,in_to_exists=off,semijoin=off,subquery_cache=off"; set @test_default_opt_switch = @@optimizer_switch; set @in_exists = "materialization=off,in_to_exists=on,semijoin=off,subquery_cache=off"; ------------------------------------------------------------------------- Schema requires partial matching, but data analysis discoveres there is no need. This is possible only if all outer columns are not NULL. ------------------------------------------------------------------------- create table t1 (a1 char(8) not null, a2 char(8) not null); create table t2 (b1 char(8), b2 char(8)); insert into t1 values ('1 - 00', '2 - 00'); insert into t1 values ('1 - 01', '2 - 01'); insert into t2 values ('1 - 00', '2 - 00'); insert into t2 values ('1 - 01', NULL ); insert into t2 values (NULL , '2 - 02'); insert into t2 values (NULL , NULL ); insert into t2 values ('1 - 02', '2 - 02'); select * from t1 where (a1, a2) not in (select * from t2 where b1 is not null and b2 is not null); a1 a2 1 - 01 2 - 01 select a1, a2, (a1, a2) not in (select * from t2) as in_res from t1; a1 a2 in_res 1 - 00 2 - 00 0 1 - 01 2 - 01 NULL drop table t1, t2; ------------------------------------------------------------------------- NULLs in the outer columns, no NULLs in the suqbuery ------------------------------------------------------------------------- create table t1 (a1 char(8), a2 char(8)); create table t2 (b1 char(8) not null, b2 char(8) not null); insert into t1 values (NULL , '2 - 00'); insert into t1 values ('1 - 01', '2 - 01'); insert into t1 values (NULL , NULL ); insert into t2 values ('1 - 00', '2 - 00'); insert into t2 values ('1 - 01', '2 - 01'); insert into t2 values ('1 - 02', '2 - 00'); select * from t1 where (a1, a2) not in (select * from t2 where b1 is not null and b2 is not null); a1 a2 select a1, a2, (a1, a2) not in (select * from t2) as in_res from t1; a1 a2 in_res NULL 2 - 00 NULL 1 - 01 2 - 01 0 NULL NULL NULL select * from t1 where (a1, a2) in (select * from t2 where b1 is not null and b2 is not null); a1 a2 1 - 01 2 - 01 select a1, a2, (a1, a2) in (select * from t2) as in_res from t1; a1 a2 in_res NULL 2 - 00 NULL 1 - 01 2 - 01 1 NULL NULL NULL drop table t1, t2; ------------------------------------------------------------------------- NULLs in the outer column, NULLs in the subquery, there is no value match in any column, but there is a partial match such that some of the matching NULLs are in the outer columns, the other NULLs are in the inner columns. ------------------------------------------------------------------------- create table t1 (a1 char(1), a2 char(1), a3 char(1)); create table t2 (b1 char(1), b2 char(1), b3 char(1)); insert into t1 values ('c', NULL, 'a'); insert into t2 values (NULL, 'x', NULL); insert into t2 values (NULL, 'y', NULL); insert into t2 values ('o', 'z', 'p'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 3 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res c NULL a NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 3 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 3 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res c NULL a NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 3 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res c NULL a NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch = @test_default_opt_switch; drop table t1, t2; create table t1 (a1 char(1), a2 char(1) not null, a3 char(1)); create table t2 (b1 char(1), b2 char(1), b3 char(1)); insert into t1 values (NULL, 'y', NULL); insert into t2 values ('v', 'x', NULL); insert into t2 values (NULL, 'y', 'w'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res NULL y NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res NULL y NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res NULL y NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch = @test_default_opt_switch; drop table t1, t2; ------------------------------------------------------------------------- There is only one column in the subquery to complement the NULLs in the outer reference. It is a NULL column, so a match is guaranteed. ------------------------------------------------------------------------- create table t1 (a1 char(1), a2 char(1), a3 char(1)); create table t2 (b1 char(1), b2 char(1), b3 char(1)); insert into t1 values (NULL, 'g', NULL); insert into t2 values ('z', NULL, 'y'); insert into t2 values (NULL, 'z', 'y'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res NULL g NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res NULL g NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res NULL g NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 set @@optimizer_switch = @test_default_opt_switch; drop table t1, t2; ------------------------------------------------------------------------- The intersection of the NULL bitmaps is empty because the ranges of NULL bits do not overlap. ------------------------------------------------------------------------- create table t1 (a1 char(1), a2 char(1), a3 char(1)); create table t2 (b1 char(1), b2 char(1), b3 char(1)); insert into t1 values ('b', 'g', NULL); insert into t2 values ('z', NULL, 'y'); insert into t2 values (NULL, 'z', 'y'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res b g NULL 0 EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 b g NULL set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res b g NULL 0 EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 b g NULL set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT t1.*, (a1, a2, a3) IN (select * from t2) as in_res from t1; a1 a2 a3 in_res b g NULL 0 EXPLAIN SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT * from t1 where (a1, a2, a3) NOT IN (select * from t2); a1 a2 a3 b g NULL drop table t1, t2; ------------------------------------------------------------------------- The intersection of the NULL bitmaps is non-empty, and there is a non-NULL column. ------------------------------------------------------------------------- create table t1 (a1 char(1), a2 char(1), a3 char(1) not null, a4 char(10)); create table t2 (b1 char(1), b2 char(1), b3 char(1), b4 char(1)); insert into t1 values ('a', 'g', 'x', NULL); insert into t2 values ('z', NULL, 'y', 'x'); insert into t2 values (NULL, NULL, 'x', 'y'); insert into t2 values ('x', 'w', 'z', NULL); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res a g x NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res a g x NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res a g x NULL NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 3 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 drop table t1, t2; ------------------------------------------------------------------------- Value match in one row, but the NULL complement match in another. The result must be false. ------------------------------------------------------------------------- create table t1 (a1 char(2), a2 char(1), a3 char(1) not null, a4 char(10)); create table t2 (b1 char(2), b2 char(1), b3 char(1), b4 char(1)); insert into t1 values ('99', NULL, 'j', 'f'); insert into t2 values ('01', NULL, 'y', NULL); insert into t2 values ('02', NULL, 'x', 'y'); insert into t2 values ('03', 'q', 'y', 'x'); insert into t2 values (NULL, 'q', 'm', 'p'); insert into t2 values ('m', 'z', 'j', NULL); insert into t2 values (NULL, 'z', 'b', NULL); insert into t2 values (NULL, 'z', 'a', NULL); insert into t2 values ('34', 'q', 'y', 'x'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 8 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res 99 NULL j f 0 EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 8 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 99 NULL j f set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 8 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res 99 NULL j f 0 EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 8 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 99 NULL j f set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 8 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res 99 NULL j f 0 EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 8 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 99 NULL j f drop table t1, t2; ------------------------------------------------------------------------- Test the intersection of larger number of rows with NULL, such that the number is at the boundary 32. This test is based on the implementation of MY_BITMAP which uses 32 bit words, and the intersection operation works by intersecting the bitmap word by word. ------------------------------------------------------------------------- create table t1 (a1 char(2), a2 char(2), a3 char(1), a4 char(10)) ENGINE=MyISAM; create table t2 (b1 char(2), b2 char(2), b3 char(1), b4 char(1)) ENGINE=MyISAM; insert into t1 values (NULL, '98', NULL, 'b'); insert into t1 values (NULL, '99', NULL, 'c'); insert into t2 values ('00', 'rr', 'y', NULL); insert into t2 values ('01', 'rr', 'y', NULL); insert into t2 values ('02', NULL, 'x', 'y'); insert into t2 values ('03', 'qq', 'y', 'x'); insert into t2 values ('04', 'qq', 'm', 'p'); insert into t2 values ('05', 'rr', 'y', NULL); insert into t2 values ('06', NULL, 'x', 'y'); insert into t2 values ('07', 'qq', 'y', 'x'); insert into t2 values ('08', 'qq', 'm', 'q'); insert into t2 values ('09', 'rr', 'y', NULL); insert into t2 values ('10', NULL, 'x', 'y'); insert into t2 values ('11', 'qq', 'y', 'x'); insert into t2 values ('12', 'qq', 'm', 'k'); insert into t2 values ('13', 'rr', 'y', NULL); insert into t2 values ('14', NULL, 'x', 'y'); insert into t2 values ('15', 'qq', 'y', 'x'); insert into t2 values ('16', 'qq', 'm', 's'); insert into t2 values ('17', 'rr', 'y', NULL); insert into t2 values ('18', NULL, 'x', 'y'); insert into t2 values ('19', 'qq', 'y', 'x'); insert into t2 values ('20', 'qq', 'm', 't'); insert into t2 values ('21', 'rr', 'y', NULL); insert into t2 values ('22', NULL, 'x', 'y'); insert into t2 values ('23', 'qq', 'y', 'x'); insert into t2 values ('24', 'qq', 'm', 'u'); insert into t2 values ('25', 'rr', 'y', NULL); insert into t2 values ('26', NULL, 'x', 'y'); insert into t2 values ('27', 'qq', 'y', 'x'); insert into t2 values ('28', 'qq', 'm', 'y'); insert into t2 values ('29', 'rr', 'y', NULL); insert into t2 values ('30', NULL, 'x', 'z'); insert into t2 values ('31', 'ss', 'h', NULL); insert into t2 values ('32', 'vv', 'i', NULL); the only partial matching row insert into t2 values ('33', NULL, 'j', NULL); insert into t2 values ('34', 'qq', 'y', 'x'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b NULL NULL 99 NULL c NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b NULL NULL 99 NULL c NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b NULL NULL 99 NULL c NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 change the mathcing row to be the last one in the first bitmap word update t2 set b2 = 'zz' where b1 = 33; update t2 set b2 = NULL where b1 = 31; set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b NULL NULL 99 NULL c NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 set @@optimizer_switch='partial_match_rowid_merge=off,partial_match_table_scan=on'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b NULL NULL 99 NULL c NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 set @@optimizer_switch=@in_exists; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b NULL NULL 99 NULL c NULL EXPLAIN SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 35 Using where SELECT * from t1 where (a1, a2, a3, a4) NOT IN (select * from t2); a1 a2 a3 a4 drop table t1, t2; ------------------------------------------------------------------------- All columns require partial matching (no non-null columns) ------------------------------------------------------------------------- TODO ------------------------------------------------------------------------- Both non-NULL columns and columns with NULLs ------------------------------------------------------------------------- TODO ------------------------------------------------------------------------- Covering NULL rows ------------------------------------------------------------------------- create table t1 (a1 char(8), a2 char(8)); create table t2 (b1 char(8), b2 char(8)); insert into t1 values ('1 - 00', '2 - 00'); insert into t1 values ('1 - 01', '2 - 01'); insert into t2 values ('1 - 01', NULL ); insert into t2 values (NULL , '2 - 02'); insert into t2 values (NULL , NULL ); insert into t2 values ('1 - 02', '2 - 02'); select * from t1 where (a1, a2) not in (select * from t2); a1 a2 select a1, a2, (a1, a2) not in (select * from t2) as in_res from t1; a1 a2 in_res 1 - 00 2 - 00 NULL 1 - 01 2 - 01 NULL insert into t2 values ('1 - 01', '2 - 01'); select * from t1 where (a1, a2) not in (select * from t2); a1 a2 select a1, a2, (a1, a2) not in (select * from t2) as in_res from t1; a1 a2 in_res 1 - 00 2 - 00 NULL 1 - 01 2 - 01 0 select * from t1 where (a1, a2) in (select * from t2); a1 a2 1 - 01 2 - 01 select a1, a2, (a1, a2) in (select * from t2) as in_res from t1; a1 a2 in_res 1 - 00 2 - 00 NULL 1 - 01 2 - 01 1 drop table t1, t2; ------------------------------------------------------------------------- Covering NULL columns ------------------------------------------------------------------------- this case affects only the rowid-merge algorithm set @@optimizer_switch="partial_match_rowid_merge=on,partial_match_table_scan=off"; create table t1 (a1 char(8) not null, a2 char(8), a3 char(8) not null); create table t2 (b1 char(8) not null, b2 char(8), b3 char(8) not null); insert into t1 values ('1 - 00', '2 - 00', '3 - 00'); insert into t1 values ('1 - 01', '2 - 01', '3 - 01'); insert into t2 values ('1 - 01', NULL, '3 - x1'); insert into t2 values ('1 - 02', NULL, '3 - 02'); insert into t2 values ('1 - 00', NULL, '3 - 00'); select * from t1 where (a1, a2, a3) not in (select * from t2); a1 a2 a3 1 - 01 2 - 01 3 - 01 select *, (a1, a2, a3) not in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 1 select * from t1 where (a1, a2, a3) in (select * from t2); a1 a2 a3 select *, (a1, a2, a3) in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 0 drop table t1, t2; create table t1 (a1 char(8), a2 char(8), a3 char(8) not null); create table t2 (b1 char(8), b2 char(8), b3 char(8) not null); insert into t1 values ('1 - 00', '2 - 00', '3 - 00'); insert into t1 values ('1 - 01', '2 - 01', '3 - 01'); insert into t2 values (NULL, NULL, '3 - x1'); insert into t2 values (NULL, NULL, '3 - 02'); insert into t2 values (NULL, NULL, '3 - 00'); select * from t1 where (a1, a2, a3) not in (select * from t2); a1 a2 a3 1 - 01 2 - 01 3 - 01 select *, (a1, a2, a3) not in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 1 select * from t1 where (a1, a2, a3) in (select * from t2); a1 a2 a3 select *, (a1, a2, a3) in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 0 drop table t1, t2; ------------------------------------------------------------------------- Covering NULL row, and a NULL column ------------------------------------------------------------------------- create table t1 (a1 char(8) not null, a2 char(8), a3 char(8)); create table t2 (b1 char(8), b2 char(8), b3 char(8)); insert into t1 values ('1 - 00', '2 - 00', '3 - 00'); insert into t1 values ('1 - 01', '2 - 01', '3 - 01'); insert into t2 values ('1 - 01', NULL, '3 - x1'); insert into t2 values (NULL , NULL, NULL ); insert into t2 values ('1 - 00', NULL, '3 - 00'); select * from t1 where (a1, a2, a3) not in (select * from t2); a1 a2 a3 select *, (a1, a2, a3) not in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 NULL select * from t1 where (a1, a2, a3) in (select * from t2); a1 a2 a3 select *, (a1, a2, a3) in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 NULL drop table t1, t2; ------------------------------------------------------------------------- Covering NULL row, and covering NULL columns ------------------------------------------------------------------------- create table t1 (a1 char(8) not null, a2 char(8), a3 char(8)); create table t2 (b1 char(8), b2 char(8), b3 char(8)); insert into t1 values ('1 - 00', '2 - 00', '3 - 00'); insert into t1 values ('1 - 01', '2 - 01', '3 - 01'); insert into t2 values (NULL, NULL, NULL); insert into t2 values (NULL, NULL, NULL); select * from t1 where (a1, a2, a3) not in (select * from t2); a1 a2 a3 select *, (a1, a2, a3) not in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 NULL select * from t1 where (a1, a2, a3) in (select * from t2); a1 a2 a3 select *, (a1, a2, a3) in (select * from t2) as in_res from t1; a1 a2 a3 in_res 1 - 00 2 - 00 3 - 00 NULL 1 - 01 2 - 01 3 - 01 NULL drop table t1, t2; ------------------------------------------------------------------------- Small buffer for the rowid_merge partial match algorithm that forces reverting to table scan partial match. ------------------------------------------------------------------------- set @save_rowid_merge_buff_size = @@rowid_merge_buff_size; set @@rowid_merge_buff_size = 0; create table t1 (a1 char(2), a2 char(2), a3 char(1), a4 char(10)); create table t2 (b1 char(2), b2 char(2), b3 char(1), b4 char(1)); insert into t1 values (NULL, '98', NULL, 'b'); insert into t1 values (NULL, '99', NULL, 'c'); insert into t2 values ('00', 'rr', 'y', NULL); insert into t2 values ('01', 'rr', 'y', NULL); insert into t2 values ('02', NULL, 'x', 'y'); insert into t2 values ('03', 'qq', 'y', 'x'); set @@optimizer_switch='partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 4 Using where SELECT t1.*, (a1, a2, a3, a4) IN (select * from t2) as in_res from t1; a1 a2 a3 a4 in_res NULL 98 NULL b 0 NULL 99 NULL c 0 drop table t1, t2; set @@rowid_merge_buff_size = @save_rowid_merge_buff_size; ------------------------------- Part 2: Test cases for bugs. ------------------------------- drop table if exists t1, t2; # # LP BUG#608744 # set @@optimizer_switch="materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=off"; create table t1 (a1 char(1), a2 char(1)); insert into t1 values (NULL, 'b'); create table t2 (b1 char(1), b2 char(2)); insert into t2 values ('a','b'), ('c', 'd'); select * from t1 where (a1, a2) NOT IN (select b1, b2 from t2); a1 a2 drop table t1,t2; # # LP BUG#601156 # CREATE TABLE t1 (a1 int DEFAULT NULL, a2 int DEFAULT NULL); INSERT INTO t1 VALUES (NULL,2), (4,NULL),(100,100); CREATE TABLE t2 (b1 int DEFAULT NULL, b2 int DEFAULT NULL); INSERT INTO t2 VALUES (6,NULL), (NULL,0),(1000,1000); insert into t2 select seq,seq from seq_2000_to_2100; set @@optimizer_switch='materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=on'; set @tmp_optimizer_switch=@@optimizer_switch; set optimizer_switch='derived_merge=off,derived_with_keys=off'; EXPLAIN EXTENDED SELECT * FROM (SELECT * FROM t1 WHERE a1 NOT IN (SELECT b2 FROM t2)) table1; id select_type table type possible_keys key key_len ref rows filtered Extra 1 PRIMARY ALL NULL NULL NULL NULL 3 100.00 2 DERIVED t1 ALL NULL NULL NULL NULL 3 100.00 Using where 3 MATERIALIZED t2 ALL NULL NULL NULL NULL 104 100.00 Warnings: Note 1003 /* select#1 */ select `table1`.`a1` AS `a1`,`table1`.`a2` AS `a2` from (/* select#2 */ select `test`.`t1`.`a1` AS `a1`,`test`.`t1`.`a2` AS `a2` from `test`.`t1` where !((`test`.`t1`.`a1`,`test`.`t1`.`a1` in ( (/* select#3 */ select `test`.`t2`.`b2` from `test`.`t2` ), (`test`.`t1`.`a1` in on distinct_key where `test`.`t1`.`a1` = ``.`b2`))))) `table1` set optimizer_switch=@tmp_optimizer_switch; DROP TABLE t1, t2; # # LP BUG#613009 Crash in Ordered_key::get_field_idx # set @@optimizer_switch='materialization=on,semijoin=off,partial_match_rowid_merge=on,partial_match_table_scan=off'; create table t1 (a1 char(4) DEFAULT NULL, a2 char(4) DEFAULT NULL); insert into t1 values (NULL, 'a21'), (NULL, 'a22'), ('xxx','xxx'); insert into t1 select seq,seq from seq_2000_to_2100; explain select * from t1 where (a1, a2) not in (select a1, a2 from t1); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 104 Using where 2 MATERIALIZED t1 ALL NULL NULL NULL NULL 104 select * from t1 where (a1, a2) not in (select a1, a2 from t1); a1 a2 drop table t1; # # LP BUG#680058 void Ordered_key::add_key(rownum_t): # Assertion `key_buff_elements && cur_key_idx < key_buff_elements' failed # create table t1 (f1 char(1), f2 char(1)); insert into t1 values ('t', '0'), ('0', 't'); create table t2 (f3 char(1), f4 char(1)); insert into t2 values ('t', NULL), ('t', NULL), ('d', 'y'); set @@optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off,semijoin=off'; select * from t1 where (f1, f2) not in (select * from t2); f1 f2 0 t drop table t1, t2; # # LP BUG#809245 Second assertion `bit < (map)->n_bits' with partial_match_merge # CREATE TABLE t1 (d varchar(32)) ; INSERT INTO t1 VALUES ('r'); CREATE TABLE t2 ( a int, c varchar(32)) ; INSERT INTO t2 VALUES (5,'r'); CREATE TABLE t3 ( a int NOT NULL , d varchar(32)) ; INSERT INTO t3 VALUES (10,'g'); set @@optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off,in_to_exists=off'; EXPLAIN SELECT * FROM t1 WHERE (t1.d , t1.d) NOT IN ( SELECT t3.d , t2.c FROM t3 LEFT JOIN t2 ON t3.a = t2.a); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 MATERIALIZED t3 system NULL NULL NULL NULL 1 2 MATERIALIZED t2 system NULL NULL NULL NULL 1 SELECT * FROM t1 WHERE (t1.d , t1.d) NOT IN ( SELECT t3.d , t2.c FROM t3 LEFT JOIN t2 ON t3.a = t2.a); d r set @@optimizer_switch='materialization=off,in_to_exists=on'; EXPLAIN SELECT * FROM t1 WHERE (t1.d , t1.d) NOT IN ( SELECT t3.d , t2.c FROM t3 LEFT JOIN t2 ON t3.a = t2.a); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t3 system NULL NULL NULL NULL 1 2 DEPENDENT SUBQUERY t2 system NULL NULL NULL NULL 1 SELECT * FROM t1 WHERE (t1.d , t1.d) NOT IN ( SELECT t3.d , t2.c FROM t3 LEFT JOIN t2 ON t3.a = t2.a); d r drop table t1, t2, t3; # # LP BUG#809266 Diverging results with partial_match_rowid_merge=on # CREATE TABLE t1 (c int) ; INSERT INTO t1 VALUES (0),(0); CREATE TABLE t2 (a int, b int) ; INSERT INTO t2 VALUES (6,3), (9,NULL); set @@optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off,in_to_exists=off'; EXPLAIN SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT b, a FROM t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT b, a FROM t2); c 0 0 EXPLAIN SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT a, b FROM t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT a, b FROM t2); c 0 0 set @@optimizer_switch='materialization=off,in_to_exists=on'; EXPLAIN SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT b, a FROM t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT b, a FROM t2); c 0 0 EXPLAIN SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT a, b FROM t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 2 SUBQUERY t2 ALL NULL NULL NULL NULL 2 Using where SELECT * FROM t1 WHERE (6, 4 ) NOT IN (SELECT a, b FROM t2); c 0 0 drop table t1, t2; # # LP BUG#856152 Wrong result with NOT IN subquery and partial_match_rowid_merge # CREATE TABLE t1 ( f1 integer NOT NULL , f2 integer) ; INSERT INTO t1 VALUES (3,3),(48,NULL),(49,1); CREATE TABLE t2 ( f3 int) ; INSERT INTO t2 VALUES (5); set @@optimizer_switch='in_to_exists=off,materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off'; EXPLAIN SELECT * FROM t2 WHERE ( 3 , 1 ) NOT IN ( SELECT f1 , f2 FROM t1 ); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 system NULL NULL NULL NULL 1 2 MATERIALIZED t1 ALL NULL NULL NULL NULL 3 SELECT * FROM t2 WHERE ( 3 , 1 ) NOT IN ( SELECT f1 , f2 FROM t1 ); f3 5 set @@optimizer_switch='in_to_exists=on,materialization=off'; EXPLAIN SELECT * FROM t2 WHERE ( 3 , 1 ) NOT IN ( SELECT f1 , f2 FROM t1 ); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t2 system NULL NULL NULL NULL 1 2 SUBQUERY t1 ALL NULL NULL NULL NULL 3 Using where SELECT * FROM t2 WHERE ( 3 , 1 ) NOT IN ( SELECT f1 , f2 FROM t1 ); f3 5 drop table t1, t2; # # LP BUG#869036 Wrong result with in_to_exists=ON and NOT IN # create table outer_sq (f1 char(1), f2 char(1)); insert into outer_sq values (NULL, 'c'), ('g', 'c'); create table inner_sq (f3 char(1), f4 char(1)); insert into inner_sq values(null, 'i'), ('v', null); All three strategies below must produce the same result. set @@optimizer_switch='in_to_exists=off,materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off'; SELECT outer_sq.*, (f1, f2) IN (select * from inner_sq) from outer_sq; f1 f2 (f1, f2) IN (select * from inner_sq) NULL c NULL g c 0 SELECT * from outer_sq where (f1, f2) NOT IN (select * from inner_sq); f1 f2 g c set @@optimizer_switch='in_to_exists=off,materialization=on,partial_match_rowid_merge=off,partial_match_table_scan=on'; SELECT outer_sq.*, (f1, f2) IN (select * from inner_sq) from outer_sq; f1 f2 (f1, f2) IN (select * from inner_sq) NULL c NULL g c 0 SELECT * from outer_sq where (f1, f2) NOT IN (select * from inner_sq); f1 f2 g c set @@optimizer_switch='in_to_exists=on,materialization=off'; SELECT outer_sq.*, (f1, f2) IN (select * from inner_sq) from outer_sq; f1 f2 (f1, f2) IN (select * from inner_sq) NULL c NULL g c 0 SELECT * from outer_sq where (f1, f2) NOT IN (select * from inner_sq); f1 f2 g c drop table outer_sq, inner_sq; # # LP BUG#893486 Wrong result with partial_match_rowid_merge , NOT IN , NULLs # CREATE TABLE t1 (a int, b int); INSERT INTO t1 VALUES (0,NULL),(2,NULL); CREATE TABLE t2 (c int, d int); INSERT INTO t2 VALUES (2,3),(4,5),(6, NULL); set @@optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off,in_to_exists=off'; EXPLAIN SELECT * FROM t1 WHERE (a, b) NOT IN (SELECT c, d FROM t2); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 3 SELECT * FROM t1 WHERE (a, b) NOT IN (SELECT c, d FROM t2); a b 0 NULL SELECT a, b, (a, b) NOT IN (SELECT c, d FROM t2) subq_res FROM t1; a b subq_res 0 NULL 1 2 NULL NULL EXPLAIN SELECT * FROM t1 WHERE (a, b) NOT IN (SELECT c, d FROM t2 WHERE d is not NULL); id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t1 ALL NULL NULL NULL NULL 2 Using where 2 MATERIALIZED t2 ALL NULL NULL NULL NULL 3 Using where SELECT * FROM t1 WHERE (a, b) NOT IN (SELECT c, d FROM t2 WHERE d is not NULL); a b 0 NULL SELECT a, b, (a, b) NOT IN (SELECT c, d FROM t2 WHERE d is not NULL) subq_res FROM t1; a b subq_res 0 NULL 1 2 NULL NULL drop table t1,t2; set @@optimizer_switch=@save_optimizer_switch;