Example of adding and deleting range partitions in MySQL 5.5

##Check the amount of data in the partition to be processed and export it as a backupmysql> select count(*) from baby_account_change_log where updated_time >'2016-12-01 00:00:00' and updated_time <'2017-01-01 00:00:00';
+----------+
| count(*) |
+----------+
|66252| 
+----------+
1 row in set (0.23 sec)

##Export backupmysql> select * into outfile '/tmp/baby_account_change_log_p1.sql' from baby_account_change_log where updated_time >'2016-12-01 00:00:00' and updated_time <'2017-01-01 00:00:00' limit 100000000000;
Query OK, 66252 rows affected (2.71 sec)


##Confirm that you want to process the partitionmysql> explain partitions select count(*) from baby_account_change_log where updated_time >'2016-12-01 00:00:00' and updated_time <'2017-01-01 00:00:00';

+----+-------------+-------------------------------+------------+-------+---------------+---------+---------+------+------+--------------------------+
| id | select_type | table | partitions | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------------------------------+------------+-------+---------------+---------+---------+------+------+--------------------------+
| 1 | SIMPLE | baby_account_change_log | p1 | index | NULL | PRIMARY | 8 | NULL | 66252 | Using where; Using index | 
+----+-------------+-------------------------------+------------+-------+---------------+---------+---------+------+------+--------------------------+

##Delete partitionmysql> alter table baby_account_change_log drop partition p0;
Query OK, 0 rows affected (0.01 sec)

#Error message: delete the partition storing the maximum value mysql> alter table baby_account_change_log add partition(PARTITION p13 VALUES LESS THAN (unix_timestamp('2017-12-31 23:59:59')));
ERROR 1481 (HY000): MAXVALUE can only be used in last partition definition

#Delete the partition storing the maximum valuemysql> alter table baby_account_change_log drop partition p12;

##Add a new partitionmysql> alter table baby_account_change_log add partition(PARTITION p12 VALUES LESS THAN (unix_timestamp('2017-12-31 23:59:59')));