PERMUTATIONS()

All functions > ARRAY > PERMUTATIONS()

Returns all ordered 2-element selections from the input array as an array of 2-element arrays.

Signatures

Returns: All ordered pairs of distinct positions

PERMUTATIONS(array: ARRAY<T>) → ARRAY<ARRAY<T>>

Notes

• Always selects ordered pairs of two elements (fixed arity)
• Supports scalar arrays, arrays of rows (ARRAY<ROW(...)>), and nested arrays (ARRAY<ARRAY<T>>)
• Uses distinct positions: the same value at two indices yields two ordered pairs
• Returns an empty array when fewer than two elements are available

See also

• Array functions

Examples

SELECT
    -- All ordered pairs
    f1 := PERMUTATIONS(ARRAY(1, 2, 3)),
    -- Two-element array
    f2 := PERMUTATIONS(ARRAY('a', 'b')),
    -- Empty input array
    f3 := PERMUTATIONS(ARRAY()::BIGINT[]),
    -- Ordered pairs of rows
    f4 := PERMUTATIONS(ZIP(ARRAY(1, 2) AS x, ARRAY('a', 'b') AS y))
;