binlog_format爲statement時的同步問題

binlog_format設置爲statement時，從機採用與主機執行同樣語句的方式同步。

這時不同的函數就會有不同的影響

雙機A機:

mysql> set binlog_format=statement;
Query OK, 0 rows affected (0.00 sec)

mysql> update test set d = now() where id =1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from test;
+----+---------------------+
| id | d                   |
+----+---------------------+
|  1 | 2015-03-10 04:55:57 |
+----+---------------------+
1 row in set (0.00 sec)

mysql> select sysdate();
+---------------------+
| sysdate()           |
+---------------------+
| 2015-03-10 04:56:17 |
+---------------------+
1 row in set (0.00 sec)

雙主B機

mysql> select * from test;
+----+---------------------+
| id | d                   |
+----+---------------------+
|  1 | 2015-03-10 04:55:57 |
+----+---------------------+
1 row in set (0.00 sec)

mysql> select sysdate();
+---------------------+
| sysdate()           |
+---------------------+
| 2015-03-10 09:19:14 |
+---------------------+
1 row in set (0.00 sec)

此時AB數據一樣。

改用sysdate()
A機

mysql> update test set d = sysdate() where id =1;
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1

mysql> select * from test;
+----+---------------------+
| id | d                   |
+----+---------------------+
|  1 | 2015-03-10 04:56:34 |
+----+---------------------+
1 row in set (0.00 sec)

B機

mysql> select * from test;
+----+---------------------+
| id | d                   |
+----+---------------------+
|  1 | 2015-03-10 09:19:24 |
+----+---------------------+
1 row in set (0.00 sec)

可以看到B機更新成了本地時間，這時數據不一致了。

因此一般爲了數據一致會把參數設成row

兩臺機子都設置如下

mysql> set binlog_format=row;
Query OK, 0 rows affected (0.00 sec)

A機

mysql> update test set d = sysdate() where id =1;
Query OK, 1 row affected (0.03 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from test;
+----+---------------------+
| id | d                   |
+----+---------------------+
|  1 | 2015-03-10 05:02:44 |
+----+---------------------+
1 row in set (0.00 sec)

B機

mysql> select * from test;
+----+---------------------+
| id | d                   |
+----+---------------------+
|  1 | 2015-03-10 05:02:44 |
+----+---------------------+
1 row in set (0.00 sec)

可以看到這時結果一致了