oracle12c-rac 的tns格式

Oracle 12c RAC中的TNS格式与单节点数据库的TNS格式基本相同，只需要在TNSNAMES.ORA文件中添加RAC节点即可。下面是一个Oracle 12c RAC TNS格式的示例：

RACDB =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = racnode1)(PORT = 1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = racnode2)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = racdb)
      (SERVER = DEDICATED)
      (FAILOVER_MODE =
        (TYPE = SELECT)
        (METHOD = BASIC)
        (RETRIES = 180)
        (DELAY = 5)
      )
    )
  )

在这个示例中，RACDB是TNS名称，它包含了两个RAC节点racnode1和racnode2的地址。CONNECT_DATA部分指定了服务名、服务器类型和故障转移参数。根据您的实际情况，您需要修改HOST、PORT、SERVICE_NAME等参数来适应您的环境。