MySQL模拟Oralce闪回操作
在前面的文章中我们介绍了MySQL误操作后数据恢复(update,delete忘加where条件),大 概操作是通过sed命令把binlog中相关SQL误操作给逆向回来，然后导入SQL文件来恢复错误操作，sed相关命令也比较复杂。如果没有正则基础的 同学肯定搞不清楚在干嘛。今天无意中发现淘宝的大神（翻译高性能mysql第三版的作者之一）开发了一个补丁，该补丁能够模拟Oracle的闪回操作，这 样以来我们的MySQL也可以实现闪回咯。真是给力。注意：同样binlog格式需要是ROW
项目主页：http://mysql.taobao.org/index.php/Patch_source_code#Add_flashback_feature_for_mysqlbinlog
测试过程
1.给mysql打补丁，该补丁是针对mysql 5.5.18的版本，我测试的mysql 5.5.25版本也可以。（也可以使用我编译好了的，64位平台下的，在文中最后会有下载地址）
wget http://mysql.taobao.org/images/0/0f/5.5.18_flashback.diff
cd /usr/local/src/mysql-5.5.25a/
patch -p0 < /root/5.5.18_flashback.diff
cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql
make && make install
2.检查补丁是否应用成功，如果mysqlbinlog命令多了-B选项，那么就ok了。
[root@yayun-mysql-server ~]# mysqlbinlog --help | grep '\-B'
-B, --flashback Flashback data to start_postition or start_datetime.
[root@yayun-mysql-server ~]#
3.模拟误操作（update忘记加where条件）
(root@yayun-mysql-server) [test]> select * from tb1;
+------+--------+
| id | name |
+------+--------+
| 1 | yayun |
| 2 | atlas |
| 3 | dyy |
| 4 | nginx |
| 5 | apache |
+------+--------+
5 rows in set (0.00 sec)
(root@yayun-mysql-server) [test]> update tb1 set name='yayun';
Query OK, 4 rows affected (0.03 sec)
Rows matched: 5 Changed: 4 Warnings: 0
(root@yayun-mysql-server) [test]> select * from tb1;
+------+-------+
| id | name |
+------+-------+
| 1 | yayun |
| 2 | yayun |
| 3 | yayun |
| 4 | yayun |
| 5 | yayun |
+------+-------+
5 rows in set (0.00 sec)
(root@yayun-mysql-server) [test]>
4.开始恢复
（1）首先需要找出错误的操作语句以及position点。
(root@yayun-mysql-server) [test]> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000023 | 364 | | |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
(root@yayun-mysql-server) [test]>
可见现在正在使用的是mysql-bin.000023这个binlog
[root@yayun-mysql-server mysql]# mysqlbinlog -vv mysql-bin.000023 |egrep -i -C 20 'update|tb1'
# Warning: this binlog is either in use or was not closed properly.
BINLOG '
RgZoUw8BAAAAZwAAAGsAAAABAAQANS41LjI1YS1sb2cAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAVAAEGggAAAAICAgCAA==
'/*!*/;
# at 107
#140506 5:45:21 server id 1 end_log_pos 175 Query thread_id=3 exec_time=0 error_code=0
SET TIMESTAMP=1399326321/*!*/;
SET @@session.pseudo_thread_id=3/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=0/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8 *//*!*/;
SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=33/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
BEGIN
/*!*/;
# at 175
# at 220
#140506 5:45:21 server id 1 end_log_pos 220 Table_map: `test`.`tb1` mapped to number 35
#140506 5:45:21 server id 1 end_log_pos 337 Update_rows: table id 35 flags: STMT_END_F
BINLOG '
cQZoUxMBAAAALQAAANwAAAAAACMAAAAAAAEABHRlc3QAA3RiMQACAw8CPAAD
cQZoUxgBAAAAdQAAAFEBAAAAACMAAAAAAAEAAv///AIAAAAFYXRsYXP8AgAAAAV5YXl1bvwDAAAA
A2R5efwDAAAABXlheXVu/AQAAAAFbmdpbnj8BAAAAAV5YXl1bvwFAAAABmFwYWNoZfwFAAAABXlh
eXVu
'/*!*/;
### UPDATE test.tb1
### WHERE
### @1=2 /* INT meta=0 nullable=1 is_null=0 */
### @2='atlas' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### SET
### @1=2 /* INT meta=0 nullable=1 is_null=0 */
### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### UPDATE test.tb1
### WHERE
### @1=3 /* INT meta=0 nullable=1 is_null=0 */
### @2='dyy' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### SET
### @1=3 /* INT meta=0 nullable=1 is_null=0 */
### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### UPDATE test.tb1
### WHERE
### @1=4 /* INT meta=0 nullable=1 is_null=0 */
### @2='nginx' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### SET
### @1=4 /* INT meta=0 nullable=1 is_null=0 */
### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### UPDATE test.tb1
### WHERE
### @1=5 /* INT meta=0 nullable=1 is_null=0 */
### @2='apache' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
### SET
### @1=5 /* INT meta=0 nullable=1 is_null=0 */
### @2='yayun' /* VARSTRING(60) meta=60 nullable=1 is_null=0 */
# at 337
#140506 5:45:21 server id 1 end_log_pos 364 Xid = 40
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
开始的起点以107为准，因为107下面紧跟着BEGIN，结束的点以end_log_pos 337下一个点为准.
[root@yayun-mysql-server mysql]# mysqlbinlog -vv --start-position=337 mysql-bin.000023
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
# at 4
#140506 5:44:38 server id 1 end_log_pos 107 Start: binlog v 4, server v 5.5.25a-log created 140506 5:44:38
# Warning: this binlog is either in use or was not closed properly.
BINLOG '
RgZoUw8BAAAAZwAAAGsAAAABAAQANS41LjI1YS1sb2cAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAEzgNAAgAEgAEBAQEEgAAVAAEGggAAAAICAgCAA==
'/*!*/;
# at 337
#140506 5:45:21 server id 1 end_log_pos 364 Xid = 40
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
[root@yayun-mysql-server mysql]#
上面蓝色字体显示的很清楚了，那么结束的点就是364，因为下面紧跟着COMMIT。现在我们已经找到了日志开始起点为107，结束点为364，下面开始恢复。
[root@yayun-mysql-server mysql]# mysqlbinlog -B -vv --start-position=107 --stop-position=364 mysql-bin.000023 | mysql
[root@yayun-mysql-server mysql]#
检查是否恢复成功：
(root@yayun-mysql-server) [test]> select * from tb1;
+------+--------+
| id | name |
+------+--------+
| 1 | yayun |
| 2 | atlas |
| 3 | dyy |
| 4 | nginx |
| 5 | apache |
+------+--------+
5 rows in set (0.00 sec)
(root@yayun-mysql-server) [test]>
可见数据已经成功恢复。其实原理和我们前面通过sed操作binlog进行恢复是一样的。只是这个更简单。对于delete忘记添加where条件，恢复方法是一样的。这里不再重复。
总结:
binlog格式非常重要，无论是数据恢复还是主从复制，ROW格式都非常的给力。当然也有缺点，复制会占用过多带宽，消耗大量磁盘空间。
已经应用补丁的mysqlbinlog下载地址（64位平台，直接替换原来的即可）
http://pan.baidu.com/s/1o6jXt14
