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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 t1 as select 1 as i, 2 as x;
create table t2 as select 5 as i, 2 as x, 3 as y;
create function f() returns table (ct1 t1, ct2 t2) language sql as $$
select t1, t2 from t1 join t2 on t1.x = t2.x
$$;
CREATE FUNCTION
select *, (ct1).*, (ct2).*, (ct2).i from f();
| ct1 | ct2 | i | x | i | x | y | i |
|---|---|---|---|---|---|---|---|
| (1,2) | (5,2,3) | 1 | 2 | 5 | 2 | 3 | 5 |
SELECT 1