argMin

CREATE TABLE salary
(
    user String,
    salary UInt32
)
ENGINE = Memory AS
SELECT *
FROM VALUES(('worker', 1000), ('manager', 3000), ('director', 5000));

SELECT argMin(user, salary) FROM salary;

┌─argMin(user, salary)─┐
│ worker               │
└──────────────────────┘

CREATE TABLE test
(
    a Nullable(String),
    b Nullable(Int64)
)
ENGINE = Memory AS
SELECT *
FROM VALUES((NULL, 0), ('a', 1), ('b', 2), ('c', 2), (NULL, NULL), ('d', NULL));

SELECT argMin(a, b), min(b) FROM test;

┌─argMin(a, b)─┬─min(b)─┐
│ a            │      0 │
└──────────────┴────────┘

SELECT argMin(a, (b, a)), min(tuple(b, a)) FROM test;

┌─argMin(a, (b, a))─┬─min((b, a))─┐
│ a                 │ (0,NULL)    │
└───────────────────┴─────────────┘