The Net Assistant is a GUI tool that can help you configure your Oracle communications. It supports wizards and configuration windows for the Net listener, Configuration Manager, Advanced Security, and Oracle database server nodes. It reads and modifies the tnsname.ora file, the sqlnet.ora file, and the listener.ora file, which store configuration parameters for Oracle communications. The "tns" in tnsnames stands for Transparent Network Substrate, which is the technology built into Net that allows it to communicate with any standard network protocol (like TCP/IP).

Even though manually created configuration files can be read and modified by the Oracle8i Net Assistant, many DBA's continue to manually support their configuration files as they have in the past.
Follow along in the simulation to add a new database node in the Net Assistant.
View Net 8 Assistant
As you probably realized, all this wizard does is make an entry in our tnsnames.ora file. Here is how it will appear after this session; note the new ADDRESS_LIST parameter.

# E:\ORACLE\ORA81\NETWORK\ADMIN\
   TNSNAMES.ORA 
   Configuration
File:E:\Oracle\Ora81\NETWORK\ADMIN\
   tnsnames.ora
# Generated by Oracle Net Assistant

TESTDB =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 
      CAROLSPC
      (PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = orcl.carol.org)
    )
  )

ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 
      carolspc)
      (PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = orcl.carol.org)
    )
  )

As you can see, the Net Assistant is a great tool for making easy changes to the parameter files. Because each database server and Oracle Net client has a tnsnames.ora file, most organizations create a "master" tnsnames.ora file and "push" the file to clients on a periodic basis. Tivoli Courier is commonly used for this task, but other software distribution tools work just as well. Remember, there are two cases in which you should add a multiple-service name for a single database:

1. When you want to define multiple listeners (on separate posts) for a single database
2. When you are using OPS and you want to add a Net service to map a request to another Oracle instance

The next lesson explores the entries in the parameter file (tnsnames.ora) maintained by the Net Assistant.

Click the link below to practice adding another node yourself.
Add Net Service