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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 12.4 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.3.1 20191121 (Red Hat 8.3.1-5), 64-bit |
2 rows affected
user_id | user_name |
---|---|
1 | user_1 |
2 | user_2 |
4 rows affected
message_id | sender_id | message_text |
---|---|---|
1 | 1 | m1 |
2 | 1 | m2 |
3 | 2 | m3 |
4 | 2 | m4 |
ERROR: insert or update on table "message" violates foreign key constraint "message_sender_id_fkey"
DETAIL: Key (sender_id)=(56) is not present in table "user_".