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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?.
WITH emp (id, fname, name) AS (
VALUES (1, 'A', 'A'),
(2, 'C', 'A'),
(3, 'B', 'B')
)
SELECT DISTINCT ON (name) id, fname, name
FROM emp
ORDER BY name, fname, id
| id | fname | name |
|---|---|---|
| 1 | A | A |
| 3 | B | B |
SELECT 2