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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 table1(id smallserial, how_many_to_generate int);
insert into table1 (how_many_to_generate) values (1),(0),(2),(0),(1) returning *;
CREATE TABLE
| id | how_many_to_generate |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 2 |
| 4 | 0 |
| 5 | 1 |
INSERT 0 5
--no rows for the 2nd and 4th entry where `how_many_rows_to_generate` is 0
select id, how_many_to_generate, generate_series(1, how_many_to_generate)
from table1;
| id | how_many_to_generate | generate_series |
|---|---|---|
| 1 | 1 | 1 |
| 3 | 2 | 1 |
| 3 | 2 | 2 |
| 5 | 1 | 1 |
SELECT 4