CREATE OR REPLACE TABLE t1 (name CHAR(30), star_rating TIME);

INSERT INTO t1 VALUES ('Lord of the Ladybirds', 5);

INSERT INTO t1 VALUES ('Lord of the Ladybirds', 3);

INSERT INTO t1 VALUES ('Lady of the Flies', 1);

INSERT INTO t1 VALUES ('Lady of the Flies', 2);

INSERT INTO t1 VALUES ('Lady of the Flies', 5);

SELECT name, PERCENTILE_DISC(0.5)

  WITHIN GROUP (ORDER BY star_rating)

  OVER (PARTITION BY name) AS pc FROM t1;

mysqld: /home/bar/maria-git/server.10.3/sql/field.h:3170: Field_datetime_with_dec::Field_datetime_with_dec(uchar*, uchar*, uchar, Field::utype, const LEX_CSTRING*, uint): Assertion `dec <= 6' failed.