SET joined_subquery_requires_alias = 1; SELECT * FROM (SELECT 1 as A, 2 as B) X ALL LEFT JOIN (SELECT 3 as A, 2 as B) Y USING (B); SELECT * FROM (SELECT 1 as A, 2 as B) X ALL LEFT JOIN (SELECT 3 as A, 2 as B) USING (B); -- { serverError 206 } SELECT * FROM (SELECT 1 as A, 2 as B) ALL LEFT JOIN (SELECT 3 as A, 2 as B) Y USING (B); -- { serverError 206 } set joined_subquery_requires_alias = 0; SELECT * FROM (SELECT 1 as A, 2 as B) ALL LEFT JOIN (SELECT 3 as A, 2 as B) Y USING (B);