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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?.
SELECT t.opening_hours->0->x.k->'opens'
FROM (VALUES ('[{"monday":{"opens":730,"closes":2300}},{"tuesday":{"opens":730,"closes":2300}},{"wednesday":{"opens":730,"closes":2300}},{"thursday":{"opens":730,"closes":2300}},{"friday":{"opens":730,"closes":2300}},{"saturday":{"opens":730,"closes":2300}},{"sunday":{"opens":730,"closes":2300}}]'::jsonb)) AS t
(opening_hours)
CROSS JOIN LATERAL (SELECT jok.k
FROM jsonb_object_keys(t.opening_hours->0) WITH ORDINALITY jok
(k,
o)
ORDER BY jok.o
LIMIT 1) x;
| ?column? |
|---|
| 730 |