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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 cities (
"id" INTEGER,
"name" VARCHAR(9),
"lat" FLOAT,
"lng" FLOAT,
"submitted_by" INTEGER
);
INSERT INTO cities
("id", "name", "lat", "lng", "submitted_by")
VALUES
('1', 'Pyongyang', '39.0392', '125.7625', '15'),
('2', 'Oslo', '59.9139', '10.7522', '8'),
('3', 'Hebron', '31.5326', '35.0998', '8'),
('4', 'Hebron', '31.5326', '35.0998', '10'),
('5', 'Paris', '48.8566', '2.3522', '12'),
('6', 'Hebron', '31.5326', '35.0998', '7');
CREATE TABLE
INSERT 0 6
SELECT name, count(name)::int FROM cities GROUP BY name
UNION ALL
SELECT 'Total', COUNT(*) FROM cities
| name | count |
|---|---|
| Hebron | 3 |
| Pyongyang | 1 |
| Oslo | 1 |
| Paris | 1 |
| Total | 6 |
SELECT 5