MySQL范围分区RANGE TO_DAY（DtCol）与RANGE COLUMN（DtCol）之间的区别

Question

我想了解一下，如果RANGE TO_DAY（DateCol）和RANGE COLUMN（DateCol）按日期划分MySQL RANGE之间有任何区别。

MySQL版本：5.7.12

示例测试脚本：

CREATE TABLE log_tbl_1 (
  id bigint(20) NOT NULL AUTO_INCREMENT,
  stime datetime not NULL,
  primary KEY id (id, stime)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
  PARTITION BY RANGE COLUMNS( stime ) (
    PARTITION p20180401 VALUES LESS THAN ('2018-04-02'),
    PARTITION p20180402 VALUES LESS THAN ('2018-04-03'),
    PARTITION p20180403 VALUES LESS THAN ('2018-04-04'),
    PARTITION p20180404 VALUES LESS THAN ('2018-04-05'),
    PARTITION p20180405 VALUES LESS THAN ('2018-04-06'),
    PARTITION p20180406 VALUES LESS THAN ('2018-04-07')
    );

 CREATE TABLE log_tbl_2 (
  id bigint(20) NOT NULL AUTO_INCREMENT,
  stime datetime not NULL,
  primary KEY id (id, stime)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
  PARTITION BY RANGE(to_days(stime)) (
    PARTITION t20180401 VALUES LESS THAN (to_days('2018-04-02')),
    PARTITION t20180402 VALUES LESS THAN (to_days('2018-04-03')),
    PARTITION t20180403 VALUES LESS THAN (to_days('2018-04-04')),
    PARTITION t20180404 VALUES LESS THAN (to_days('2018-04-05')),
    PARTITION t20180405 VALUES LESS THAN (to_days('2018-04-06')),
    PARTITION t20180406 VALUES LESS THAN (to_days('2018-04-07'))
    );

任何帮助将不胜感激。在此先感谢：）