create or replace table t1 (

  x int,

  a varchar(255)

) with system versioning partition by system_time (partition p1 history, partition pn current);

insert into t1 (x) values (1), (2), (3), (4);

update t1 set a= 'foo' limit 3;

update t1 set a= 'bar' limit 4;

select * from t1;

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

| x    | a    |

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

|    1 | bar  |

|    2 | foo  |

|    3 | foo  |

|    4 | NULL |

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

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

| x    | a    |

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

|    1 | bar  |

|    2 | bar  |

|    3 | bar  |

|    4 | bar  |

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