oracle restart介绍
第一部分
一,基本概念
Oracle restart是一个11g新加入的特性
作用：安装Oracle restart后，当由于硬件或者软件故障加载失败或者数据库由于某些原因重启后，oracle的各种组件能够自动重启
可以重启的组件内容：(也就是由oracle restart管理的组件)
| Component |
| Notes |
| Database instance |
| Oracle Restart can accommodate multiple databases on a single host computer. |
| Oracle Net listener |
| - |
| Database services |
| Does not include the default service created upon installation because it is automatically managed by Oracle Database, and does not include any default services created during database creation. |
| Oracle Automatic Storage Management (Oracle ASM) instance |
| - |
| Oracle ASM disk groups | Restarting a disk group means mounting it. |
| Oracle Notification Services (ONS) |
| In a standalone server environment, ONS can be used in Oracle Data Guard installations for automating failover of connections between primary and standby database through Fast Application Notification (FAN). ONS is a service for sending FAN events to integrated clients upon failover |
Oracle restart会周期性的检查监控这些组件的健康状况，如果发现某个组件不健康，这个组件就会重启
使用范围：单实例环境（ＲＡＣ使用Ｃｌｕｓｔｅｒｗａｒｅ管理）
二，关于启动时的依赖
Oracle restart会根据组件的依赖性按顺序启动。举例说明：
if database files are stored in Oracle ASM disk groups, then beforestarting the database instance, Oracle Restart ensures that the Oracle ASMinstance is started and the required disk groups are mounted. Likewise, if acomponent must be shut down, Oracle Restart ensures that dependent componentsare cleanly shut down first.
同样，在组件关闭的时候，会确保依赖组件事先关闭
Oraclerestart也管理数据库实例和监听之间的弱依赖性，即启动数据库实例的时候oracle restart会尝试启动监听，如果监听启动失败了，database instance仍然会启动，即使是监听后来启动失败了，oracle database instance 也不会down掉或者重启。
三，使用oracle restart启动，停止组件
当需要的时候Oracle restart会自动重启各种组件。并且当手动关闭系统及关机oracle restart会自动依次的停止oracle 组件。
oracle提供了一个oracle restart的管理工具SRVCTL来手动的启停各种组件
如果在使用oracle restart的时候，oracle强烈推荐使用SRVCTL这个工具来启停各种组件。
不同：使用srvctl与使用sqlplus（或者是其他工具如lsnrctl等）重大不同在于：
1.当使用srvctl启动一个组件时，所有的依赖组件会按照顺序依次先启动起来
2.当使用sqlplus启动一个组件时，其他的依赖组件不会自动启动，你必须确保所有的依赖组件已经全部启动你才能启动这个实例。
四，oracle restart的启动与关闭
使用SRVCTL启动关闭oracle restart
五，oracle restart配置
所有被管理的组件信息都要整合到oracle restartconfiguration中
下面是执行操作是否会自动整合到oracle restartconfiguration中的两个表
第一，创建的动作是否能把创建的组件自动的add到oraclerestart configuration 中
Create Operationsand the Oracle Restart Configuration
| Create Operation |
| Created Component Automatically Added to Oracle Restart Configuration? |
| Create a database with OUI or DBCA |
| Yes |
| Create a database with the CREATE DATABASE SQL statement |
| No |
| Create an Oracle ASM instance with OUI, DBCA, or ASMCA |
| Yes |
| Create a disk group (any method) |
| Yes |
| Add a listener with NETCA |
| Yes |
| Create a database service with SRVCTL |
| Yes |
| Create a database service by modifying the SERVICE_NAMES initialization parameterFoot 1 |
| No |
| Create a database service with DBMS_SERVICE.CREATE_SERVICE |
| No |
| Create a standby database |
| No |
Footnote 1 Not recommendedwhen Oracle Restart is in use
第二，通过Delete/Drop/Remove动作是否能将删除的组件自动的从oracle restart configuration 中删除
Delete/Drop/RemoveOperations and the Oracle Restart Configuration
| Operation |
| Deleted Component Automatically Removed from Oracle Restart Configuration? |
| Delete a database with DBCA |
| Yes |
| Delete a database by removing database files with operating system commandsFoot 1 |
| No |
| Delete a listener with NETCA |
| Yes |
| Drop an Oracle ASM disk group (any method) |
| Yes |
| Delete a database service with SRVCTL |
| Yes |
| Delete a database service by any other means |
| No |
Footnote 1 Not recommended
第二部分
Oraclerestart在data guard中的使用