You can link to data in remote databases, in cloud storage, or in connected file systems or the local file system. You can also use Database Links to access objects on another database.

When you link to data in a remote database or in cloud storage or in connected file systems or the local file system, the target object produced is an external table or a view. When you select that target table or view on the Data Load, explore page in Database Actions, the source preview for the object shows the current data in the source object.

Linking to columns in a remote database, to files in cloud storage, or in connected file systems or the local file system can be useful when the source data is being continually updated. For example, if you have a database table with columns that are updated for each new sales transaction, and you have run a data load job that links columns of the source table to targets in your Oracle Autonomous Database, then those targets have the new sales data as it is updated in the source.

In addition, you can use Database Links to access objects on another database. Using Database Links, the other database need not be an Oracle Database system.

• Query External Data with Autonomous Database
  Describes packages and tools to query and validate data with Autonomous Database.
• Use Database Links with Autonomous Database
  You can create database links from an Autonomous Database to another Autonomous Database, to other Oracle databases, or to non-Oracle databases. In addition, you can create database links from other databases to an Autonomous Database.