MariaDB [db]> create table t (c char(4)) engine=Columnstore;

Query OK, 0 rows affected (0.632 sec)

MariaDB [db]> insert into t values ('foo');

Query OK, 1 row affected (0.194 sec)

MariaDB [db]> insert into t values ('foobar');

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

MariaDB [db]> update t set c = 'foobar';

Query OK, 1 row affected (0.276 sec)

Rows matched: 1  Changed: 1  Warnings: 0

MariaDB [db]> select * from t;

+------+

| c    |

+------+

| foob |

+------+

1 row in set (0.034 sec)