12C-OCP升级1z-060-004

Which statement is true about Oracle Net Listener?

A. It acts as the listening endpoint for the Oracle database instance for all local and nonlocal

user connections.

B. A single listener can service only one database instance and multiple remote client

connections.

C. Service registration with the listener is performed by the process monitor (LREG)

process of each database instance.

D. The listener.ora configuration file must be configured with one or more listening protocol

addresses to allow remote users to connect to a database instance.

E. The listener.ora configuration file must be located in the

ORACLE_HOME/network/admin directly.

Answer: C

A错， Oracle的本地连接不需要监听就能够进行连接，

B错， 监听可以为整个服务器中的所有的数据库进行服务，并不是只为单一的服务器进行服务的

C正确 LREG进程是12C新添加的进程，在11g中，实例注册到监听是通过PMON进程来完成的，在12C中，有LREG进程来完成实例注册的工作
LREG Listener Registration ProcessRegisters the instance with the listeners
LREG notifies the listeners about instances, services, handlers, and endpoint.Database instances, Oracle ASM instances, Oracle RAC

D错，

E错， 在操作系统级别，有TNS_ADMIN这个环境变量，我们通过定义这个环境变量，可以任意指定Oracle网络配置文件的位置。