Loading into Columnstore from SELECT changes values

create table innotab(

`col1` mediumint(8) unsigned NOT NULL,

`col2` decimal(9,2) DEFAULT NULL) 

ENGINE=InnoDB DEFAULT CHARSET=latin1;

insert into innotab (col1,col2) values(999,888.88);

create table cstab (

`col1` mediumint(8) unsigned NOT NULL,

`col2` decimal(9,2) DEFAULT NULL) 

ENGINE=Columnstore DEFAULT CHARSET=latin1;

set session columnstore_use_import_for_batchinsert=ALWAYS;

insert into cstab select * from innotab;

ERROR 9999 (HY000): Values saturated

MariaDB [test]> select * from innotab;

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

| col1 | col2   |

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

|  999 | 888.88 |

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

1 row in set (0.000 sec)

MariaDB [test]> select * from cstab;

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

| col1     | col2        |

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

| 16777215 | -9999999.99 |

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

1 row in set (0.006 sec)