我即将复制一个频繁读/写的生产数据库。按照 MySQL 手册页上的说明，我执行以下命令
mysql> FLUSH TABLES WITH READ LOCK;
Query OK, 0 rows affected (0.16 sec)
mysql> show master status;
+------------------+-----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+-----------+--------------+------------------+
| mysql-bin.000061 | 717697391 | | |
+------------------+-----------+--------------+------------------+
1 row in set (0.00 sec)
然后我通过执行以下命令开始我的备份过程
shell> mysqldump --lock-all-table --databases first second third -u root -p > dbdump.sql
然后我运行以下命令
mysql> show master status;
+------------------+-----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+-----------+--------------+------------------+
| mysql-bin.000061 | 717697462 | | |
+------------------+-----------+--------------+------------------+
1 row in set (0.00 sec)
mysql> show master status;
+------------------+-----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+-----------+--------------+------------------+
| mysql-bin.000061 | 717697462 | | |
+------------------+-----------+--------------+------------------+
1 row in set (0.00 sec)
如果执行“READ LOCK”语句后表已经被锁定，为什么连续两次“show master status”命令的坐标位置不同？我应该为我的复制使用哪个位置值？
顺便问一下，我需要跑步吗
mysql> UNLOCK TABLES;
备份过程之后？或者当 mysqldump 完成时，表将自动解锁。