使用sql apply来升级数据库

在oracle10g开始，可以使用sql apply在堆数据库进行滚动升级。

使用sql apply滚动升级的好处

1数据库的停机时间很短，停机的时间也就是switchover的时间

2排出了由于重新编译pl/sql的停止时间

3可以再不影响主库的情况下验证升级的数据库版本。

使用sql apply滚动升级的要求

1数据库不能使dg broker配置的一部分

2dg保护模式必须要不是最高可用，要不是最大性能

3逻辑库的log_archive_dest_n初始化参数必须设置成optional来确保当逻辑备库在升级的时候，主库可以处理

4compatible初始化参数设置，要升级x到y，那么在主库和备库上都要设置compatible成x.

在滚动升级期间，dg配置有混合的数据库版本，数据库保护模式在这期间不可用，考虑在dg配置中有第二个备库来提供数据保护。

准备升级

1设置compatible初始化参数

2获取未支持表的信息

3找出不支持的数据类型

4创建一个逻辑备库

升级数据库

Table 11-1Step-by-Step Procedure to Upgrade Oracle Database Software

Step	Description
1	Stop SQL Apply and upgrade the logical standby database
2	Restart SQL Apply
3	Monitor events on the upgraded standby database
4	Begin a switchover
5	Determine if unsupported objects were modified during the upgrade
6	Complete the switchover and activate user applications
7	Upgrade the former primary database
8	Start SQL Apply
9	Optionally, raise the compatibility level on both databases
10	Monitor events on the new logical standby database
11	Optionally, perform another switchover

 1停止sql apply

SQL> ALTER DATABASE STOP LOGICAL STANDBY APPLY;

2重启sql apply

SQL> ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;

3监控

SELECT SYSDATE, APPLIED_TIME FROM V$LOGSTDBY_PROGRESS;
SELECT EVENT_TIMESTAMP, EVENT, STATUS FROM DBA_LOGSTDBY_EVENTS
ORDER BY EVENT_TIMESTAMP;
4开始切换

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO LOGICAL STANDBY;
5检查对象是否修改

6完成转换并激活用户程序

SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO LOGICAL PRIMARY;

7升级前主库

8开始sql apply

ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE NEW PRIMARY db_link_to_b;
9提高compatible

10监控新逻辑备库的事件

11可选的在来次转换

Optionally, perform another switchover of the databases so Database A is once again running in the primary database role (as shown in Figure 11-1).

1. To begin the switchover, issue the following statement on Database B:

   SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO LOGICAL STANDBY;
   
   

   This command waits for existing transactions to complete. After existing transactions have completed, users still connected to Database B will get errors when they try to run transactions on Database B. They should log off immediately and reconnect to Database A.

2. On Database A issue the following query:

   SQL> SELECT SWITCHOVER_STATUS FROM V$DATABASE;
   
   SWITCHOVER_STATUS
   --------------------
   TO PRIMARY
   
   

3. When the query returns TO PRIMARY, complete the switchover by issuing the following statement on Database A:

   SQL> ALTER DATABASE COMMIT TO SWITCHOVER TO LOGICAL PRIMARY;
   
   

   Database A is again running in the primary database role. Users can log in to Database A and begin their work.

4. Start SQL Apply by issuing the following statement on Database B:

   SQL> ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;