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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?.
version |
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PostgreSQL 13.7 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-10), 64-bit |
3 rows affected
7 rows affected
user_id | country | category | cat_cnt |
---|---|---|---|
123 | USA | tourism | 3 |
123 | USA | business | 2 |
124 | Ireland | tourism | 1 |
124 | Ireland | business | 1 |
user_id | country | coalesce | cat_cnt |
---|---|---|---|
123 | USA | tourism | 3 |
123 | USA | business | 2 |
124 | Ireland | tourism | 1 |
124 | Ireland | business | 1 |
125 | Japan | ------ | 0 |