STDDEV_POP ( [ DISTINCT ] <expression> )

STDDEV_POP ( [ DISTINCT ] expr ) OVER ([ PARTITION BY expr][ ORDER BY expr  ] [<window_frame>])

CREATE TABLE coordinates(
x_axis decimal (5,2),
y_axis decimal (7,2),
z_axis decimal (10,2));

INSERT INTO coordinates VALUES (2, 5, 9), 
(7, 15, null), 
(8, 1, 12), 
(5, 7, 0), 
(8, 6, 1), 
(null, 7, 11);

SELECT x_axis, STDDEV_POP(z_axis), STDDEV_POP(y_axis) 
FROM coordinates GROUP BY x_axis;

+--------+-------------------+--------------------+
| x_axis | STDDEV_POP(z_axis)| STDDEV_POP(y_axis) |
+--------+-------------------+--------------------+
| 5.00   | 0.000000          | 0.000000           |
| 2.00   | 0.000000          | 0.000000           |
| NULL   | 0.000000          | 0.000000           |
| 8.00   | 5.500000          | 2.500000           |
| 7.00   | NULL              | 0.000000           |
+--------+-------------------+--------------------+

CREATE TABLE player_scores(player_name VARCHAR(50), player_id VARCHAR(10), 
    1st_qtr_score DECIMAL(5,2), 2nd_qtr_score DECIMAL(5,2), 
    3rd_qtr_score DECIMAL(5,2), 4th_qtr_score DECIMAL(5,2), 
    yearly_total AS 1st_qtr_score + 2nd_qtr_score + 3rd_qtr_score + 4th_qtr_score PERSISTED DECIMAL(5,2));

INSERT INTO player_scores VALUES
    ('Steve', '119','22.50','72.00', '63.00', '45.00'),
    ('Jack', '432', '90.10', '78.00','88.20', '92.20'),
    ('Jim', '779','75.00', '68.90','55.70', '72.00'), 
    ('Eve', '189','91.50', '88.10', '95.00', '94.50'),
    ('Shelia','338', '75.60', '72.00', '81.10', '78.40'),
    ('June', '521', '81.00', '87.30','76.80','82.20'),
    ('Martin', '674','98.80', '95.10', '88.00', '96.40');

SELECT player_name, 1st_qtr_score, 
ROUND(STDDEV_POP(yearly_total) OVER (ORDER BY player_name, yearly_total)) AS STDDEV_POP
FROM player_scores
ORDER BY player_name;

+-------------+---------------+------------+
| player_name | 1st_qtr_score | STDDEV_POP |
+-------------+---------------+------------+
| Eve         |         91.50 |          0 |
| Jack        |         90.10 |         10 |
| Jim         |         75.00 |         42 |
| June        |         81.00 |         36 |
| Martin      |         98.80 |         38 |
| Shelia      |         75.60 |         37 |
| Steve       |         22.50 |         57 |
+-------------+---------------+------------+

SELECT player_name, 1st_qtr_score, 2nd_qtr_score,
ROUND(STDDEV_POP(1st_qtr_score) OVER (ORDER BY player_name, 1st_qtr_score, 2nd_qtr_score ROWS UNBOUNDED PRECEDING)) AS STDDEV_POP
FROM player_scores
ORDER BY player_name;

+-------------+---------------+---------------+------------+
| player_name | 1st_qtr_score | 2nd_qtr_score | STDDEV_POP |
+-------------+---------------+---------------+------------+
| Eve         |         91.50 |         88.10 |          0 |
| Jack        |         90.10 |         78.00 |          1 |
| Jim         |         75.00 |         68.90 |          7 |
| June        |         81.00 |         87.30 |          7 |
| Martin      |         98.80 |         95.10 |          8 |
| Shelia      |         75.60 |         72.00 |          9 |
| Steve       |         22.50 |         72.00 |         23 |
+-------------+---------------+---------------+------------+