58題、choose two
Which two statements are true about Oracle network connections?
A) A listener may listen on behalf of only one database instance at a time.
B) A server process checks a user's authentication credentials and creates a session if the credentials are valid.
C) A connection request from a client is always first received by a listener running on the port that is used for the connection request for the database server.
D) The listener always spawns a new server process to deal with each new connection.
E) The listener continuously monitors a connection after the user process connects to a service handler.
Answer：BC
(解析：監聽可以監聽多個實例;如果是共享連接，則不會總是派生出server進程對應一個新的連接;一個連接建立後，就不需要監聽再進行監視了，比如可以把監聽停止，但是不會影響當前的連接;來自客戶機的連接請求總是首先由運行在用於數據庫服務器連接請求的端口上的偵聽器接收。來自3組：1015267481)