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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 t1 (id int);
INSERT INTO t1 VALUES (1),(3),(5);
CREATE TABLE t2 (id int2);
INSERT INTO t2 VALUES (1),(2),(3),(4),(5);
CREATE TABLE
INSERT 0 3
CREATE TABLE
INSERT 0 5
INSERT INTO t1 (id)
SELECT t2.id FROM t2
WHERE NOT EXISTS (
SELECT * FROM t1
WHERE t2.id = t1.id);
INSERT 0 2
SELECT * FROM t1 ORDER BY id;
| id |
|---|
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
SELECT 5