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Lesson 11Application connection with SQL
ObjectiveDescribe the Two Ways to connect to Remote Databases.

Describe Two Ways to connect to Remote Databases

Connections to remote databases can be made by specifying either service names or connect strings. Service names are used by SQL*Net version 2 and Net8 and take the following syntax: 

emp@my_db

Connect strings originated with SQL*Net version 1 and specify the full connection. In the following example, the t means a TCP/IP connection; host is the name of the remote processor; and database is the name of the databases on that processor. 
sqlplus /@t:host:database

These connect strings can be saved in the Oracle database dictionary for use by distributed SQL. They are created with the create database link command and are stored in the DBA_USER-DBLINKS meta-table: 
create public database link ny_emp for
  ny_emp@t:myhost:mydatabase

The next lesson examines the features of SQL*Net version 1.

Oracle TNS Quiz

Before moving on to the next lesson, click the Quiz link below to check your mastery of the material we have covered in the past few lessons with a short multiple-choice quiz.
Oracle TNS - Quiz

On Your Own

If you have access to an Oracle server, click the On Your link to practice searching your Oracle topology.
Searching Oracle Toplogy