https://www.oceanbase.com/docs/common-oceanbase-database-cn-1000000000220230
文档说：
您可以将当前分区表的分区类型修改为任意其他类型。
但是，我的操作：
CREATE TABLE tbl2(c1 INT, c2 DATETIME, PRIMARY KEY(c1, c2))
PARTITION BY HASH(c1) PARTITIONS 4;
ALTER TABLE tbl2 PARTITION BY KEY(c1) PARTITIONS 10;
ERROR 1235 (0A000): re-partition a patitioned table not supported