二进制日志文件安全的的删除方法（删除前请备份）：
语法： PURGE { BINARY | MASTER } LOGS { TO 'log_name' | BEFORE datetime_expr }
mysql> SHOW BINARY LOGS;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 27702 |
| mysql-bin.000002 | 1063490 |
| mysql-bin.000003 | 733 |
| mysql-bin.000004 | 150 |
| mysql-bin.000005 | 126 |
| mysql-bin.000006 | 126 |
| mysql-bin.000007 | 126 |
| mysql-bin.000008 | 126 |
| mysql-bin.000009 | 126 |
| mysql-bin.000010 | 126 |
| mysql-bin.000011 | 381 |
| mysql-bin.000012 | 126 |
| mysql-bin.000013 | 1625 |
+------------------+-----------+
mysql> PURGE BINARY LOGS TO 'mysql-bin.000010'; #把此二进制日志文件之前的都删除
Query OK, 0 rows affected (0.04 sec)
mysql> SHOW BINARY LOGS;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000010 | 126 |
| mysql-bin.000011 | 381 |
| mysql-bin.000012 | 126 |
| mysql-bin.000013 | 1625 |