CREATE does not allow tables with versioning columns only, but ALTER does

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

# ERROR 4128 (HY000): Table `t1` must have at least one temporal column

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

# Query OK, 0 rows affected (0.29 sec)

set system_versioning_alter_history=keep;

# Query OK, 0 rows affected (0.00 sec)

alter table t1 drop i;

# Query OK, 0 rows affected (0.69 sec)

# Records: 0  Duplicates: 0  Warnings: 0

MariaDB [test]> show create table t1 \G

*************************** 1. row ***************************

       Table: t1

Create Table: CREATE TABLE `t1` (

  `s` timestamp(6) GENERATED ALWAYS AS ROW START,

  `e` timestamp(6) GENERATED ALWAYS AS ROW END,

  PERIOD FOR SYSTEM_TIME (`s`, `e`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1 WITH SYSTEM VERSIONING

1 row in set (0.00 sec)