1603
1603
insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2);
1604
1604
explain select * from t1 where b=1 or b is null order by a;
1605
1605
id select_type table type possible_keys key key_len ref rows Extra
1607
1607
select * from t1 where b=1 or b is null order by a;