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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
INSERT 0 12
CREATE INDEX
| time | metric_a | metric_b | value |
|---|---|---|---|
| 2023-08-15 04:00:00 | A | A | 1 |
| 2023-08-15 04:00:00 | A | B | 2 |
| 2023-08-15 04:00:00 | A | C | 1 |
| 2023-08-15 04:00:00 | B | A | 2 |
| 2023-08-15 04:00:00 | B | B | 3 |
| 2023-08-15 04:00:00 | B | C | 4 |
SELECT 6