TIDY UP THE ENVIRONMENT, BY RETURNING TO THE ORIGINAL CONFIGURATION

5. Tidy up the environment, by returning to the original configuration:

alter system set local_listener='' scope=memory;alter system set service_names='' scope=memory;alter system set dispatchers='' scope=memory;alter system set shared_servers=0 scope=memory;alter system register;

Stop the listener from an operating system prompt with lsnrctl stop

newlist.

Unset the TNS_ADMIN variable: on Linux, export TNS_ADMIN=" or on

Windows, remove the TNS_ADMIN registry key.

Two-Minute Drill

PA R T I

Configure and Manage the Oracle Network

• The server-side files are the listener.ora and (optionally)

sqlnet.ora files.

• The client-side files are the tnsnames.ora and (optionally)

• The Oracle Net files live by default in ORACLE_HOME/network/admin, or in

whatever directory the TNS_ADMIN variable points to.

• Name resolution can be local (with a tnsnames.ora file) or central (with

an LDAP directory).

• Easy Connect does not need any name resolution.

• One listener can listen for many databases.

• Many listeners can connect to one database.

• Instance registration with listeners can be static (by coding details in the

listener.ora file) or dynamic (by the PMON process updating

the listener).

• Each user process has a persistent connection to its dedicated server process.

Use the Oracle Shared Server Architecture

• User processes connect to dispatchers; these connections are persistent.

• All dispatchers place requests on a common queue.

• Shared server processes dequeue requests from the common queue.

• Each dispatcher has its own response queue.

• Shared server processes place results onto the appropriate dispatcher’s

response queue.

• The dispatchers fetch results back to the appropriate user process.

• Shared server is configured with (as a minimum) two instance parameters:

dispatchers and shared_servers.