SELECT
    *
FROM
    as_table([])
INTERSECT ALL
SELECT
    *
FROM
    as_table([])
;

SELECT
    *
FROM
    as_table([])
INTERSECT ALL
SELECT
    1 AS x,
    2 AS y
;

SELECT
    1 AS x,
    2 AS y
INTERSECT ALL
SELECT
    *
FROM
    as_table([])
;