How to Create DB Link in Database

What is database Link ?

A database link (DBlink) is a definition of how to establish a connection from one Oracle database to another.

The following link types are supported:

·         Private database link - belongs to a specific schema of a database. Only the owner of a private database link can use it.

·         Public database link - all users in the database can use it.

·         Global database link - defined in an OID or Oracle Names Server. Anyone on the network can use it.

Syntax to Create Database Link

CREATE [SHARED][PUBLIC] DATABASE LINK link_name

      [CONNECT TO user IDENTIFIED BY password]

      [AUTHENTICATED BY user IDENTIFIED BY password]

         [USING 'connect_string']

Example:

CREATE  DATABASE LINK dblink@linktodb -- DB Link Name

      CONNECT TO apps IDENTIFIED BY apps

--      AUTHENTICATED BY apps IDENTIFIED BY apps

         USING 'testdb.sa.loc:1620/TEST' -- Host Name          

         

         

How to Use DB Link

select * from per_all_assignments_f@dblink@linktodb