Oracle DB Links

What is DB link? 

Oracle DB links are used to connect to different sources through procedures/views. It helps creating views or materialized views by pulling data from different db sources.

To check the db links present in the database, the below query can be used.

Query:

select * from dba_db_links;

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)

 SHARD_INTERNAL                                     VARCHAR2(3)

 VALID                                              VARCHAR2(3)

 INTRA_CDB                                          VARCHAR2(3)

Create a DB link:

Create or replace database link "<DB link name>" connect as "<remote username>" identified by "<Remote user password>" using "<Remote DB TNS details>";

Hope this helps. Please let me know if you face any issues, comment below.