130.Which two statements are true regarding listeners? (Choose two.)

130.Which two statements are true regarding listeners? (Choose two.)
A.Listeners use only the TCP/IP protocol.
B.Multiple listener processes can run simultaneously on a host.
C.Multiple database instances can be registered with a single listener.
D.The listener-related errors can be traced only at the administrative level.
E.Only one database instance can be registered with a single listener at any time.
答案：BC
A:错误，还有ipc
Interprocess Communication (IPC)
A protocol that client applications use that resides on the same node as the listener to communicate with the database. IPC can provide a faster local connection than TCP/IP.
B:正确
LSNRCTL> status
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date                28-JUL-2016 09:54:17
Uptime                    0 days 0 hr. 0 min. 35 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/oracle/11g/network/admin/listener.ora
Listener Log File         /u01/oracle/diag/tnslsnr/wahaha3/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=wahaha3.com)(PORT=1521)))
Services Summary...
Service "hrtest" has 1 instance(s).
  Instance "hrtest", status UNKNOWN, has 1 handler(s) for this service...
Service "wahaha3" has 2 instance(s).
  Instance "wahaha3", status UNKNOWN, has 1 handler(s) for this service...
  Instance "wahaha3", status READY, has 1 handler(s) for this service...
Service "wahaha3XDB" has 1 instance(s).
  Instance "wahaha3", status READY, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL> status lis2
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=0.0.0.0)(PORT=1522)))
STATUS of the LISTENER
------------------------
Alias                     lis2
Version                   TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date                28-JUL-2016 09:55:05
Uptime                    0 days 0 hr. 0 min. 4 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/oracle/11g/network/admin/listener.ora
Listener Log File         /u01/oracle/diag/tnslsnr/wahaha3/lis2/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=0.0.0.0)(PORT=1522)))
The listener supports no services
The command completed successfully
C:正确
LSNRCTL> status
Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.3.0 - Production
Start Date                28-JUL-2016 07:32:27
Uptime                    0 days 0 hr. 55 min. 42 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/oracle/11g/network/admin/listener.ora
Listener Log File         /u01/oracle/diag/tnslsnr/wahaha3/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=wahaha3.com)(PORT=1521)))
Services Summary...
Service "hrtest" has 1 instance(s).
  Instance "hrtest", status UNKNOWN, has 1 handler(s) for this service...
Service "wahaha3" has 2 instance(s).
  Instance "wahaha3", status UNKNOWN, has 1 handler(s) for this service...
  Instance "wahaha3", status READY, has 1 handler(s) for this service...
Service "wahaha3XDB" has 1 instance(s).
  Instance "wahaha3", status READY, has 1 handler(s) for this service...
The command completed successfully
D:错误
  这个不会写到那里的，写的地方通过lsnrctl status中可以看到Listener Log File
  如果在监听文件中没有指定路径，那么默认路径为
  $ORACLE_BASE/diag/tnslsnr/$ORACLE_SID/listener/alert/log.xml
  如果在监听文件中指定了ADR_BASE_listener的路径那么
  $ADR_BASE_listener/diag/tnslsnr/$ORACLE_SID/listener/alert/log.xml
E:错误