After RAC ONE NODE Failover and relocate ，instance_number 和 oracle_sid changes

        一套RAC ONE NODE 数据库由于asmb进程异常导致数据库failover，reolocate回原来的节点后，发现instance_number由1变为2，oracle_sid由xxx_1 变为xxx_2。由于数据库部署有ogg和其他需要指定sid的业务，所以请求官方解决sid 改变和asmb异常原因。

        提交sr后，官方给出如下文档，仔细对比后发现比较符合我的情况：

未failover之前是xxx_1(1节点），failover之后xxx_1(2节点）---与官方阐述是一致的；此后，我又relocate回到1节点，sid为xxx_2(1节点）。那么此时数据库认为1节点是主节点

relocate回1节点时是switchover也是符合文档中的解释的。

Instance Name changes during RAC One Node Failover/Switchover (文档 ID 1540629.1)

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In this Document Purpose   Scope   Details APPLIES TO: Oracle Database - Enterprise Edition - Version 11.2.0.1 to 11.2.0.3 [Release 11.2] Oracle Database - Enterprise Edition - Version 12.1.0.2 to 12.1.0.2 [Release 12.1] Information in this document applies to any platform. PURPOSE  Instance Name changes during RAC One NODE Failover / Switchover SCOPE  Instance Name changes DETAILS   INSTANCE / NODE CRASH (FAILOVER):      When the node goes down due to abnormal termination (  kill -9 or due to unknow reasons) Grid Infrastructure performs the following:  First cluster tries to restart the instance in same node.   If it is unsuccessful then it will start the instance in other node.  If the instance name is orcl_1, when it failover to node 2 it will be still orcl_1.            INSTANCE RELOCATE MANUALLY(SWITCHOVER):     When Manually switchover is performed for relocating orcl_1 from Node1 to Node 2 (Instance Relocation) Grid Infrastructure performs the following: It will first create pfile( init.ora) automatically in node 2. In node 2 it will use the new pfile and start instance with a new name, i.e. orcl_2, this is due to both instances are required to be up and running for active sessions on the original node to complete or time out. Post switchover, it uses new instance name i.e. orcl_2