Those query of issue could not be supported. #2483#2493
Those query is forbidden:
query1: select * from t1 where k1=(select k1 from t2 where t1.k2=t2.k2);
query2: select * from t1 where k1=(select distinct k1 from t2 where t1.k2=t2.k2);
Only sum, max, min, avg and count function could appear on select clause for correlated subquery. #2420
Those query is legal:
query1: select * from t1 where k1=(select avg(k1) from t2 where t1.k2=t2.k2);