Which statement is true about Oracle Net Listener?
Which statement is true about Oracle Net Listener?
The Oracle Net Listener must be configured with one or more listening protocol addresses in the listener.ora configuration file to allow remote users to connect to a database instance. This setup ensures that the listener can accept connections over different network protocols, which is critical for remote connectivity. Without these protocol addresses, the listener cannot facilitate incoming network connections to the Oracle database.
C would not be correct for 12c, since PMON handled this process in earlier releases, but for 12c it is the LREG that handles service registration
D is correct http://www.dba86.com/docs/oracle/11.2/network.112/e41945/listenercfg.htm#NETAG292
The Answer is 100% D guys... Havok is correct on why C is WRONG. Reference below will confirm LREG handles that proces. It also confirms why D is correct. https://docs.oracle.com/database/121/NETAG/listenercfg.htm#NETAG292
Answer should be D，LREG do the register work instead of PMON in 12c
C. Service registration with the listener is performed by the listener registration process monitor (LREG) process of each database instance. Reference: http://docs.oracle.com/database/121/NETAG/listenercfg.htm
A is wrong because you can make local connections without going through a listener. B is wrong because many databases can register with a listener. D is wrong because you don’t have to configure a listening protocol address(es) in istener.ora. If not specified, it will simply default to TCP port 1521. E is wrong because Oracle will also look in $TNS_ADMIN directory or /etc.
Answer is C. But option C is a little bit different: C. Service registration with the listener is performed by the listener registration process monitor (LREG) process of each database instance. Not D.
Agree with Havok: Listener Registration Process (LREG) The listener registration process (LREG) registers information about the database instance and dispatcher processes with the Oracle Net Listener. When an instance starts, LREG polls the listener to determine whether it is running. If the listener is running, then LREG passes it relevant parameters. If it is not running, then LREG periodically attempts to contact it. Note: In releases before Oracle Database 12c, PMON performed the listener registration.
The listener forwards client requests to supported services. These services are dynamically registered with the listener. This dynamic registration feature is called service registration. The registration is performed by the Listener Registration (LREG) process. Dynamic service registration does not require any manual configuration in the listener.ora file.
When confused which option is correct, better to find out the incorrect options. Agree with @hggz
Since the version of database is not mentioned, we can only consider option C as it's correct for versions before 12c. Rest all options are incorrect. "In releases before Oracle Database 12c, PMON performed the listener registration."
I thing that this could be and old question and in exam 12c we will se the LREG service instead.