diff --git a/mysql-test/r/join.result b/mysql-test/r/join.result index af2d4bed592..c785c3be379 100644 --- a/mysql-test/r/join.result +++ b/mysql-test/r/join.result @@ -779,4 +779,32 @@ Field Type Null Key Default Extra Name varchar(50) YES NULL DROP VIEW v1; DROP TABLE t1,t2,tv1,tv2; +create table t1 (a int, b int); +insert into t1 values +(NULL, 1), +(NULL, 2), +(NULL, 3), +(NULL, 4); +create table t2 (a int not null, primary key(a)); +insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); +create table t3 (a int not null, primary key(a)); +insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); +flush status; +select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b; +a b a a +explain select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b; +id select_type table type possible_keys key key_len ref rows Extra +1 SIMPLE t1 ALL NULL NULL NULL NULL 4 +1 SIMPLE t2 eq_ref PRIMARY PRIMARY 4 test.t1.b 1 Using index +1 SIMPLE t3 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 Using index +We expect rnd_next=5, and read_key must be 0 because of short-cutting: +show status like 'Handler_read%'; +Variable_name Value +Handler_read_first 0 +Handler_read_key 0 +Handler_read_next 0 +Handler_read_prev 0 +Handler_read_rnd 0 +Handler_read_rnd_next 5 +drop table t1, t2, t3; End of 5.0 tests. diff --git a/mysql-test/t/join.test b/mysql-test/t/join.test index 99dd21e8ee2..a0fc7059179 100644 --- a/mysql-test/t/join.test +++ b/mysql-test/t/join.test @@ -610,4 +610,27 @@ DESCRIBE tv2; DROP VIEW v1; DROP TABLE t1,t2,tv1,tv2; + +# BUG#27939: Early NULLs filtering doesn't work for eq_ref access +create table t1 (a int, b int); +insert into t1 values + (NULL, 1), + (NULL, 2), + (NULL, 3), + (NULL, 4); + +create table t2 (a int not null, primary key(a)); +insert into t2 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); + +create table t3 (a int not null, primary key(a)); +insert into t3 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); + +flush status; +select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b; +explain select * from t1, t2, t3 where t3.a=t1.a and t2.a=t1.b; +--echo We expect rnd_next=5, and read_key must be 0 because of short-cutting: +show status like 'Handler_read%'; +drop table t1, t2, t3; + + --echo End of 5.0 tests. diff --git a/sql/sql_select.cc b/sql/sql_select.cc index 77565ca8f7b..9b27daabc0e 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -5444,8 +5444,9 @@ static void add_not_null_conds(JOIN *join) for (uint i=join->const_tables ; i < join->tables ; i++) { JOIN_TAB *tab=join->join_tab+i; - if ((tab->type == JT_REF || tab->type == JT_REF_OR_NULL) && - !tab->table->maybe_null) + if ((tab->type == JT_REF || tab->type == JT_EQ_REF || + tab->type == JT_REF_OR_NULL) && + !tab->table->maybe_null) { for (uint keypart= 0; keypart < tab->ref.key_parts; keypart++) {