=?iso-8859-1?Q?Andr=E9_H=E4nsel?= <andre(at)webkr(dot)de> 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