By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
Help with an interesting Postgres question: Why isn't an Index Only Scan used on a partition accessed via the parent table?.
CREATE TABLE
CREATE TABLE
INSERT 0 3
INSERT 0 4
| day | code | count |
|---|---|---|
| 2022-01-01 | MOBILE | 1 |
| 2022-01-01 | WEB | 3 |
| 2022-01-02 | MOBILE | 1 |
| 2022-01-02 | WEB | 3 |
| 2022-01-03 | MOBILE | 1 |
| 2022-01-03 | WEB | 3 |
| 2022-01-04 | MOBILE | 1 |
| 2022-01-04 | WEB | 3 |
| 2022-01-05 | MOBILE | 1 |
| 2022-01-05 | WEB | 3 |
SELECT 10