CREATE TABLE `yy_subscribe2` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `user_id` int(10) unsigned NOT NULL comment '用户id',
  `book_id` int(10) unsigned NOT NULL comment '小说id',
  `chapter_id` int(10) unsigned NOT NULL comment '章节id',
  PRIMARY KEY (`id`),
  key book_id(book_id),
  key user_id(user_id),
  key chapter_id(chapter_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8  
PARTITION BY RANGE (user_id) 
( 
    PARTITION s0 values LESS THAN (100000),
    PARTITION s1 values LESS THAN (200000),
    PARTITION s2 values LESS THAN (300000),
    PARTITION s3 values LESS THAN (400000),
    PARTITION s4 values LESS THAN (500000),
    PARTITION s5 values LESS THAN (600000),
    PARTITION s6 values LESS THAN (700000),
    PARTITION s7 values LESS THAN (800000),
    PARTITION s8 values LESS THAN (900000),
    PARTITION s9 values LESS THAN (1000000),
    PARTITION s10 values LESS THAN (1100000),
    PARTITION s11 values LESS THAN (1200000),
    PARTITION s12 values LESS THAN (1300000),
    PARTITION s13 values LESS THAN (1400000), 
    PARTITION s999 values LESS THAN MAXVALUE
);

mysql 建立分區報這個錯：For RANGE partitions each partition must be defined 。
是什麼原因。

另外這是一張小說的章節訂閱表。用來記錄使用者訂閱了哪本書的哪一章。目前已有3000W條數據。索引已經做了。打算用分區是否對後續的資料成長有效果？還是不用分區用別的方式？