Oracle Database Link Synonyms

Database Link: The main purpose is to access the remote database. You can directly access the remote database through the database link.

Synonym: To make distributed operations more transparent, the Oracle database has a synonym object synonym. As its name implies, it is a synonym for an object and can be used instead of an object.

 

The database link creation syntax is generally:

Create database link [db_link_name] connect to [user_name] identified by [Password] Using '[tns_name]';

Where:

[Db_link_name]: Service name of the database to be connected, that is, the real name of the database (usually Sid ).

[Usre_name]: name of the user to be connected.

[Password]: the password of the user to be connected.

[Tns_name]: the service name of the database to be connected, that is, the net8 service name created on the local machine.

Usage:

Select * from [table_name] @ [db_link_name]; insert, update, and delete are the same.

 

Example:

Database Link

Create public database link Beijing connect to Scott identified by tiger using 'tobeijing ';

Then, a link Beijing with Scott user and Beijing database is created. We can query Scott data in Beijing:

Select * from EMP @ Beijing;

In this way, the data of Scott users in Shenzhen and Beijing can be processed as a whole.

 

Synonym

Create synonym bjscottemp for EMP @ Beijing;

Therefore, you can use bjscottemp to replace the Distributed Link operation with the @ symbol EMP @ Beijing.