Hello
I thing so Agg node doesn't set width well:
postgres=# explain select a,b from twocol; QUERY PLAN
----------------------------------------------------------Seq Scan on twocol (cost=0.00..31.40 rows=2140 width=8)
(1 row)
postgres=# explain select sum(a) from twocol group by b; QUERY PLAN
----------------------------------------------------------------HashAggregate (cost=42.10..44.60 rows=200 width=8) --<
wrongshould be 4 -> Seq Scan on twocol (cost=0.00..31.40 rows=2140 width=8)
(2 rows)
Agg get width directly from outer plan, what could be wrong.
Regards
Pavel Stehule