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Help with an interesting Postgres question: Why isn't an Index Only Scan used on a partition accessed via the parent table?.
create table t (
id serial primary key,
a int,
b int,
c int
);
insert into t(a, b, c) values
( 1, 1, 1),
( 2, null, 2),
(null, 3, 3),
( 4, 4, 4);
4 rows affected
select sum(value)
from t
cross join lateral (values
(a),
(b),
(c)
) as x(value);
| sum |
|---|
| 25 |