Access from different Oracle databases through database link

By default, access between different Oracle Server databases is remotely accessed through local operations *. *

1. Create a database link
Example:
Create public database link orcl211 connect to username identified by password using '(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP) (HOST = *. *) (PORT = 1521 ))
)
(CONNECT_DATA =
(Service_name = ORCL)
)
)';

Parameter description:
Create public database link name

Connect to user name

Identified by password

Using 'Connection description'

The connection description must be in the following format _ or the service name www.bkjia.com configured in tnsnames. ora, but note that the following format must also be met in tnsnames. ora; otherwise, the connection will fail:

(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP) (HOST = *. *) (PORT = 1521 ))
)
(CONNECT_DATA =
(SERVICE_NAME = ORCL service name)
)
)

2. the syntax for accessing objects in the Linked database is as follows: Access ts_staff_info under the edubur user in orcl211
Example:
Select * from edubur. ts_staff_info @ orcl211;
Parameter description:
Select * from user name. Table Name @ remote database link name

3. view all created database link names
 
Select owner, db_link from dba_db_links;

Ower db_link
PUBLIC ORCL211.REGRESS. RDBMS. DEV. US. ORACLE. COM

4. Delete the Database Link name
Drop public database link ORCL211.REGRESS. RDBMS. DEV. US. ORACLE. COM