=?iso-8859-1?Q?Andr=E9_H=E4nsel?= <andre@xxxxxxxx> writes: > Now if you change > INSERT INTO a(a_id) SELECT generate_series(1, 20000); > to > INSERT INTO a(a_id) SELECT generate_series(1, 200000); > i.e. add a zero, the plan becomes [ not a hashed subplan ] Yeah, it won't hash the subplan if the estimated size of the hash table exceeds work_mem. In this case, boosting work_mem would be a mighty good idea. regards, tom lane