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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 3
| dts |
|---|
| 2020-01-01 00:00:00+00 |
| 2020-01-02 00:00:00+00 |
| 2020-01-03 00:00:00+00 |
| 2020-01-04 00:00:00+00 |
| 2020-01-05 00:00:00+00 |
| 2020-01-06 00:00:00+00 |
| 2020-01-07 00:00:00+00 |
| 2020-01-08 00:00:00+00 |
| 2020-01-09 00:00:00+00 |
| 2020-01-10 00:00:00+00 |
| 2020-01-11 00:00:00+00 |
| 2020-01-12 00:00:00+00 |
| 2020-01-13 00:00:00+00 |
| 2020-01-14 00:00:00+00 |
| 2020-01-15 00:00:00+00 |
| 2020-01-16 00:00:00+00 |
| 2020-01-17 00:00:00+00 |
| 2020-01-18 00:00:00+00 |
| 2020-01-19 00:00:00+00 |
| 2020-01-20 00:00:00+00 |
| 2020-01-21 00:00:00+00 |
| 2020-01-22 00:00:00+00 |
| 2020-01-23 00:00:00+00 |
| 2020-01-24 00:00:00+00 |
| 2020-01-25 00:00:00+00 |
| 2020-01-26 00:00:00+00 |
| 2020-01-27 00:00:00+00 |
| 2020-01-28 00:00:00+00 |
| 2020-01-29 00:00:00+00 |
| 2020-01-30 00:00:00+00 |
| 2020-01-31 00:00:00+00 |
| 2020-02-01 00:00:00+00 |
| 2020-02-02 00:00:00+00 |
| 2020-02-03 00:00:00+00 |
| 2020-02-04 00:00:00+00 |
| 2020-02-05 00:00:00+00 |
| 2020-02-06 00:00:00+00 |
| 2020-02-07 00:00:00+00 |
| 2020-02-08 00:00:00+00 |
| 2020-02-09 00:00:00+00 |
| 2020-02-10 00:00:00+00 |
| 2020-02-11 00:00:00+00 |
| 2020-02-12 00:00:00+00 |
| 2020-02-13 00:00:00+00 |
| 2020-02-14 00:00:00+00 |
| 2020-02-15 00:00:00+00 |
| 2020-02-16 00:00:00+00 |
| 2020-02-17 00:00:00+00 |
| 2020-02-18 00:00:00+00 |
| 2020-02-19 00:00:00+00 |
| 2020-02-20 00:00:00+00 |
| 2020-02-21 00:00:00+00 |
| 2020-02-22 00:00:00+00 |
| 2020-02-23 00:00:00+00 |
| 2020-02-24 00:00:00+00 |
| 2020-02-25 00:00:00+00 |
| 2020-02-26 00:00:00+00 |
| 2020-02-27 00:00:00+00 |
| 2020-02-28 00:00:00+00 |
| 2020-02-29 00:00:00+00 |
| 2020-07-01 00:00:00+01 |
| 2020-07-02 00:00:00+01 |
| 2020-07-03 00:00:00+01 |
| 2020-07-04 00:00:00+01 |
| 2020-07-05 00:00:00+01 |
| 2020-07-06 00:00:00+01 |
| 2020-07-07 00:00:00+01 |
| 2020-07-08 00:00:00+01 |
| 2020-07-09 00:00:00+01 |
| 2020-07-10 00:00:00+01 |
| 2020-07-11 00:00:00+01 |
| 2020-07-12 00:00:00+01 |
| 2020-07-13 00:00:00+01 |
| 2020-07-14 00:00:00+01 |
| 2020-07-15 00:00:00+01 |
| 2020-07-16 00:00:00+01 |
| 2020-07-17 00:00:00+01 |
| 2020-07-18 00:00:00+01 |
| 2020-07-19 00:00:00+01 |
| 2020-07-20 00:00:00+01 |
| 2020-07-21 00:00:00+01 |
| 2020-07-22 00:00:00+01 |
| 2020-07-23 00:00:00+01 |
| 2020-07-24 00:00:00+01 |
| 2020-07-25 00:00:00+01 |
| 2020-07-26 00:00:00+01 |
| 2020-07-27 00:00:00+01 |
| 2020-07-28 00:00:00+01 |
| 2020-07-29 00:00:00+01 |
| 2020-07-30 00:00:00+01 |
| 2020-07-31 00:00:00+01 |
SELECT 91
| mt | wd |
|---|---|
| 7 | 27 |
| 1 | 27 |
| 2 | 24 |
SELECT 3