countered in the sort.

select owner,  
accountName,  
CloseDate,  
amount,
percentile_cont(0.5) within group (order by amount) over (partition by owner)
pct_cont,
percentile_disc(0.5) within group (order by amount) over (partition by owner)
pct_disc
from opportunities  
where stageName='ClosedWon' 
and closeDate >= '2016-10-02' and closeDate <= '2016-10-09'  
order by owner, CloseDate;

With example results:

+--------+----------------+-------------+---------+------------+------------+
| owner  | accountName    | CloseDate   | amount  | pct_cont   | pct_disc   |
+--------+----------------+-------------+---------+------------+------------+
| Bill   | Babbleopia     | 2016-10-02  | 437636. | 437636.470 | 437636.47  |
|        |                |             | 7       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+
| Bill   | Thoughtworks   | 2016-10-04  | 146086. | 437636.470 | 437636.47  |
|        |                |             | 1       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+
| Bill   | Latz           | 2016-10-08  | 857254. | 437636.470 | 437636.47  |
|        |                |             | 7       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+
| Chris  | Linkbridge     | 2016-10-07  | 539977. | 619772.155 | 539977.45  |
|        |                |             | 5       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+
| Chris  | Avamm          | 2016-10-09  | 699566. | 619772.155 | 539977.45  |
|        |                |             | 6       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+
| Olivie | Devpulse       | 2016-10-05  | 834235. | 667519.110 | 500802.29  |
|        |                |             | 3       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+
| Olivie | Trupe          | 2016-10-07  | 500802. | 667519.110 | 500802.29  |
|        |                |             | 9       | 000000     |            |
+--------+----------------+-------------+---------+------------+------------+

URL: https://mariadb.com/kb/en/window-functions-columnstore-window-functions/