Remote access using an Oracle DBLink

The easiest way to access from an Oracle database to objects of another Oracle database is using a DBLink (this does not mean that it is always the most desirable, abuse of DBLinks can generate both performance as security problems).

First, you need a user who holds the create database link privilege. Then, you can create DBLink in source database (A) through this simple sentence:

  • create database link lnk_from_A_a_B connect to user identified by password using 'B';

- 'lnk_from_A_a_B ' is the link name,

- 'user' and 'password' are the user identifiers who will use the link to connect.

- 'B' is the SID of the target database.

Through this DBLink you can connect with objects in the remote database with privileges owned by the user of the creation sentence.

To reference an object of the remote database should indicate object name concatenated with '@' and the DBLink name.

Example: select * from mytable@lnk_from_A_a_B

 

Well, personally, I have

Well, personally, I have found DB links to be the simplest method of accessing from an Oracle Database to another Oracle database. But like it is said here, it isn’t certainly without its flaws. I have often seen many performance issues related with the abuse of DB links and even worse is when it affects the security. That being said, if you use it correctly and appropriately, I don’t think there would be such an issue to worry about! business continuity planning software