A database link allows you to reference objects in a remote database. Typically, the remote database will be another Oracle database, but it can be any ODBC compliant database.When accessing a remote object over a database link, the local database is acting as an Oracle client.
Remote Username: remo / remo
Private database link to a user in a remote database (To access the table in one and only SYS user from the Database).
SQL> show user
USER is “REMO”
SQL> conn / as sysdba
Connected.
SQL> desc dba_db_links;
Name Null? Type
—————————————————– ——– ————————————
OWNER NOT NULL VARCHAR2(128)
DB_LINK NOT NULL VARCHAR2(128)
USERNAME VARCHAR2(128)
HOST VARCHAR2(2000)
CREATED NOT NULL DATE
HIDDEN VARCHAR2(3)
SQL> create public database link dblink1 connect to remo identified by remo using ‘raj’;
Database link created.
Private database link to a user in a remote database, with full connection string.
CREATE DATABASE LINK dblink_remo CONNECT TO remo IDENTIFIED BY remo USING
‘(DESCRIPTION=
(ADDRESS=(PROTOCOL=TCP)(HOST=server1.example.com)(PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=HRDEV1)))’;
Public Database link(To access the table in any users from the Database).
SQL> create public database link dblink1 connect to remo identified by remo using ‘raj’;
Database link created.
Private database link to a user in the local database.
CREATE DATABASE LINK remo_local
CONNECT TO remo IDENTIFIED BY remo
USING ‘local’;
