Online Documentation for SQL Manager for Oracle
A Database link is a schema object in one database that enables you to access objects on another database. The other database need not be an Oracle system. However, to access non-Oracle systems, you must use Oracle Heterogeneous Services.
After you have created a database link, you can use it to refer to tables and views on the other database.
Database Link Editor allows you to define database link properties. It opens automatically when you create a new database link and is available on editing an existing one.
To open a database link in Database Link Editor, double-click it in the DB Explorer tree.