PRAGMA YqlSelect = 'force';

SELECT
    depname,
    empno,
    salary,
    Avg(salary) OVER (
        PARTITION BY
            depname
    )
FROM (
    VALUES
        ('develop', 11, 5200),
        ('develop', 7, 4200),
        ('develop', 9, 4500),
        ('develop', 8, 6000),
        ('develop', 10, 5200),
        ('personne', 5, 3500),
        ('personne', 2, 3900),
        ('sales', 3, 4800),
        ('sales', 1, 5000),
        ('sales', 4, 4800)
) AS empsalary (
    depname,
    empno,
    salary
);