1. CARDINALITY(x) = COUNT
2. SET(x) = DISTINCT
3. x MULTISET UNION DISTINCT y = UNION
4. x MULTISET UNION y = UNION ALL
5. x MULTISET UNION ALL y = UNION ALL
6. x MULTISET INTERSECT y = INTERSECT
7. x MULTISET INTERSECT DISTINCT y
8. x MULTISET EXCEPT y = MINUS
9. x MULTISET EXCEPT DISTINCT y
Например
WITH tax AS (
SELECT 13 a FROM dual UNION ALL
SELECT 35 a FROM dual)
SELECT x MULTISET UNION x
FROM (
SELECT cast(collect(a) AS sps.tpt_number) x, 1 flag FROM tax UNION ALL
SELECT cast(collect(a) AS sps.tpt_number) x, 2 flag FROM tax WHERE ROWNUM > 1
) t
WHERE CARDINALITY(t.x) > 0;10. POWERMULTISET -- работает как CUBE для коллекций, создает всевозможные наборы из элементов
SELECT *
FROM TABLE(POWERMULTISET(tpt_number(1, 2, 3)));11. POWERMULTISET_BY_CARDINALITY -- тоже, что и POWERMULTISET, но возвращаются строки с заданным количеством элементов
SELECT *
FROM TABLE(POWERMULTISET_BY_CARDINALITY(tpt_number(1, 2, 3), 2));
