create or replace table t1 (i int, s timestamp(6) as row start, e timestamp(6) as row end, c varchar(8), period for system_time(s,e)) with system versioning;

insert into t1 values (1,null,null,'foo');

select * from t1;

MariaDB [test]> insert into t1 values (1,null,null,'foo');

Query OK, 1 row affected (0.03 sec)

MariaDB [test]> select * from t1;

+------+----------------------------+----------------------------+------+

| i    | s                          | e                          | c    |

+------+----------------------------+----------------------------+------+

|    1 | 2017-12-28 20:13:42.655595 | 2038-01-19 05:14:07.999999 | NULL |

+------+----------------------------+----------------------------+------+

1 row in set (0.00 sec)

MariaDB [test]> create or replace table t1 (i int, s timestamp(6) as row start, e timestamp(6) as row end, c varchar(8), period for system_time(s,e)) with system versioning;

Query OK, 0 rows affected (0.22 sec)

MariaDB [test]> insert into t1 values (2,'2012-12-12 12:12:12:121212','2012-12-12 12:12:12:121212','bar');

Query OK, 1 row affected, 1 warning (0.03 sec)

MariaDB [test]> show warnings;

+---------+------+----------------------------------------+

| Level   | Code | Message                                |

+---------+------+----------------------------------------+

| Warning | 1265 | Data truncated for column 'c' at row 1 |

+---------+------+----------------------------------------+

1 row in set (0.00 sec)

MariaDB [test]> select * from t1;

+------+----------------------------+----------------------------+----------+

| i    | s                          | e                          | c        |

+------+----------------------------+----------------------------+----------+

|    2 | 2017-12-28 20:16:37.635292 | 2038-01-19 05:14:07.999999 | 2012-12- |

+------+----------------------------+----------------------------+----------+

1 row in set (0.00 sec)

MariaDB [test]> set sql_mode='strict_all_tables';

Query OK, 0 rows affected (0.00 sec)

MariaDB [test]> insert into t1 values (2,'2012-12-12 12:12:12:121212','2012-12-12 12:12:12:121212','bar');

ERROR 1406 (22001): Data too long for column 'c' at row 1