Syntax

    1. mysql> select topn_weighted(k5,k1,3) from baseall;
    2. | topn_weighted(`k5`, `k1`, 3) |
    3. +------------------------------+
    5. +------------------------------+
    6. 1 row in set (0.02 sec)
    7. mysql> select topn_weighted(k5,k1,3,100) from baseall;
    9. | topn_weighted(`k5`, `k1`, 3, 100) |
    10. +-----------------------------------+
    11. | [0, 243.325, 100.001]             |