select * from base limit 20;

select * from (select * from base limit 20) x 
    left join
    /* вот тут "криминал" */
    (select max(someId), * from some) y
    on y.baseId = x.baseId

select * from (select * from base limit 20) x 
    left join
    /* попытка уйти от "криминала" */
    (select max(someId), * from some 
         where baseId in (select baseId from base limit 20)
    ) y
    on y.baseId = x.baseId

create table baser (id int, tit text);
create table faser (id int, tit text, baserId int);

insert into baser values (1, 'baser 1');
insert into baser values (2, 'baser 2');
insert into baser values (3, 'baser 3');

insert into faser values(1, 'faser 1', 1);
insert into faser values(2, 'faser 2', 1);
insert into faser values(3, 'faser 3', 2);
insert into faser values(4, 'faser 4', 2);
insert into faser values(5, 'faser 5', 2);

select * from baser left join faser on baser.id = faser.baserId;

id	tit	   id	   tit	           baserId
1	baser 1	   1	   faser 1	   1
1	baser 1	   2	   faser 2	   1
2	baser 2	   3	   faser 3	   2
2	baser 2	   4	   faser 4	   2
2	baser 2	   5	   faser 5	   2
3	baser 3	   NULL	   NULL	           NULL

id	tit	   id	   tit	           baserId
1	baser 1	   2	   faser 2	   1
2	baser 2	   5	   faser 5	   2
3	baser 3	   NULL	   NULL	           NULL