B. Shared Server is a scalability option of Oracle. It provides a way to increase the number of supported user processes while reducing the overall memory usage. This configuration is well suited to high-volume, small-transaction-oriented systems with many users connected. Because users share processes, the number of overall idle processes is also reduced. It is not well suited for large data retrieval type applications such as decision support.

D. Users can request dedicated connections in a Shared Server configuration. Index rebuilds and data-intensive activities should be performed using dedicated server. The database cannot be started when connecting via Shared Server. So the correct answer is D.

A. A user must explicitly request a dedicated connection when a server is configured in Shared Server mode. Otherwise, the user gets a Shared Server connection. The correct parameter is (SERVER=DEDICATED).

C. The Shared Server configuration parameters exist in the init.ora file on the Oracle Server machine.

C. In Shared Server, users connect to a pool of shared resources called dispatchers. A client connects to the listener, and the listener redirects the request to a dispatcher. The dispatchers handle all the user requests for the session. Many users can share dispatchers.

D. Because the database has to be configured in Shared Server mode, you must change the init.ora file. The other choices are also configuration files, but none of them are used to configure Shared Server.

E. This is one of the tricky questions again! You can use Oracle Net Manager to configure many options and files, including tnsnames.ora and sqlnet.ora. But because Shared Server is a characteristic of the database server and not of the network, you cannot use Oracle Net Manager to configure it.

B. The DISPATCHERS parameter of the init.ora file is used to configure dispatchers, so the correct answer is option B. All the other choices are invalid parameters.

C. The System Global Area is the shared memory segment that Oracle obtains on instance startup. The Program Global Area is an area of memory used primarily during dedicated connections. The Database Buffer Cache is actually a component of the Program Global Area. Virtual Circuits are the shared memory areas to which clients bind.

C. Once a dispatcher receives a request from the user process, it places the request on the request queue. Remember that in a Shared Server environment, a request can be handled by a shared server process. This is made possible by placing the request and user information in the SGA.

C. Many users can connect to dispatchers, and dispatchers can be added dynamically. Also, each dispatcher does have its own response queue. The only one of these options that is false is option C because dispatchers can listen for only one protocol. You can configure multiple dispatchers so that each is responsible for different protocols.

D. A small PGA is maintained even though most of the user-specific information is moved to the SGA (specifically called the UGA in the Shared Pool or the Large Pool). The only information left in the reduced PGA is stack space.

B. Shared Servers can process requests from many users. The completed requests are placed into the dispatchers' response queues. The servers are configured with the SERVERS parameter. However, shared servers do not receive requests directly from dispatchers. The requests are taken from the request queue.

A. Study the steps of what happens during a request via Shared Server. Dispatchers receive requests from users and place the requests on request queues. Only dispatchers interact with client processes. Shared servers merely execute the requests and place the results back on the dispatcher's response queue.

C. Shared Server requires a shift of memory away from individual session processes to the SGA. More information has to be kept in the SGA (in the UGA) within the Shared Pool. A Large Pool is configured and is responsible for most of the SGA space allocation. Option C is the correct answer. The cache size and block buffers settings do not affect Shared Server.

C. Request queues reside in the SGA, and there is one request queue per instance. This is where shared server processes pick up requests that are made by users. Dispatchers have their own response queues, but they share a single request queue.

D. You can use several V$ views to manage the Shared Server. V$QUEUE gives information regarding the request and response queues. V$USERS and V$SESS_STATS are not valid views. V$CIRCUIT gives information about the users who are connected via Shared Server connections, and it provides the necessary information.

C. The PMON process notifies the listener after a client connection is established. This is so that the listener can keep track of the number of connections being serviced by each dispatcher.

C. You can query the V$SHARED_SERVER_MONITOR view to display information about the maximum number of connections and sessions, the number of servers started and terminated, and the server high-water mark. These numbers can help determine whether you should start more shared servers.

D. Dispatchers register with listeners so that when a listener redirects a connection to a dispatcher, the listener knows how many active connections the dispatcher is serving. The lsnrctl status command summarizes the number of connections established, connections currently active, and other valuable information regarding Shared Server. The lsnrctl services command summarizes only dispatchers and does not display any details about connections.