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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 a (
id text
);
INSERT INTO a VALUES ('A'), ('B'), ('C');
CREATE TABLE b (
id text,
val int
);
INSERT INTO b VALUES ('A',4), ('B', 5), ('B', 6), ('C', 7);
CREATE TABLE c (
id text,
val int
);
INSERT INTO c VALUES ('A', 7), ('B', 8), ('C', 9)
3 rows affected
4 rows affected
3 rows affected
select a.id, b.val, c.val
from a
left join b on a.id = b.id
left join c on a.id = c.id
| id | val | val |
|---|---|---|
| A | 4 | 7 |
| B | 5 | 8 |
| B | 6 | 8 |
| C | 7 | 9 |