To create a shared database link, use the shared keyword of the create database link
command. As shown in the following listing, you will also need to specify a schema and
password for the remote database:
create shared database link HR_LINK_SHARED
connect to current_user
authenticated by HR identified by employeeservices202
using 'hq';
The HR_LINK_SHARED database link uses the connected user??™s username and password when
accessing the HQ database, since this link specifies the connect to current_user clause. In other
to prevent unauthorized attempts to use shared links, the authenticated by clause is required for
shared links. In this example, the account used for authentication is an application user??™s account,
Chapter 17: Managing Distributed Databases 609
but you can also use an empty schema (that no user will ever log into) for authentication. The
authentication account must have the CREATE SESSION system privilege. When users use the
HR_LINK_SHARED link, connections will use the HR account on the remote database.
NOTE
The authentication username and password are visible to users with
access to the SYS.LINK$ table in Oracle Database 10g Release 1 or
earlier.
If you change the password on the authentication account, you will need to drop and recreate
each database link that references the account. To simplify maintenance, create an account that is
only used for authentication of shared database link connections.
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