Get DBlinks information

In Oracle you can connect to and query other databases with DBlinks, and that's almost like having the data in your local database ... Until you have problems like latency or shutting down instances needed to work with your local instance; if you didn't install or design your local database chances are you have DBlinks and you don't know.

Therefore, if you want to know information about DBlinks in your database, you can issue this SQL sentences:

SQL> column DB_LINK format a30
SQL> column name format a30
SQL> column value format a50

SQL> select name, value from v$parameter where name like '%dblink%';

NAME                           VALUE                                                                                       
------------------------------ --------------------------------                                          
dblink_encrypt_login           FALSE                                                                                       

SQL> select OWNER, DB_LINK, HOST, CREATED from dba_db_links;

OWNER                DB_LINK              HOST            CREATED                       
--------------- -------------------- -------------------- ---------                     
PUBLIC          DBLINK1              MYHOST01             25-MAY-08                     
PUBLIC          DBLINK2              MYHOST02             25-MAY-08                     
PUBLIC          DBLINK3              MYHOST03             25-MAY-08                     
PUBLIC          DBLINK4              MYHOST04             25-MAY-08