Always Free ADW Does Not Allow Private End Point Networking
NOTE: If your Always Free APEX Service has no activity for 7 consecutive days, the instance will be automatically stopped. Your data will be preserved, and you can restart the instance to continue using it. If the instance remains stopped for 3 months, it will be reclaimed.
CLICK HERE - To learn More About Always Free Database Instances in the Oracle Cloud.
Potential Issues with Always Free
When spinning up an Autonomous Data Warehouse in the Oracle Cloud OCI please take note that the always free versions do not allow you to update Network Access and set the database to a private end point in your VCN. This means unless you upgrade to a paid version of the database you cannot incorporate the data as part of a Bastion Server or configure it for TLS access. A potential work around may be to set your ADW database Access Control list to enable, but in doing so, you will be restricted to accessing the database from only Public IP addresses that you configure under Access Control. This may also limit third-party clients such as Oracle SQL Developer, Alteryx, etc.. for using a database wallet only. Using a JDBC Thin Driver with JDK8 or above is necessary to utilize TLS.
About Connecting to an Autonomous Database Instance
After you create database users, applications and tools connect to Autonomous Databases using Oracle Net Services (also known as SQL*Net). Oracle Net Services enables a network session from a client application to an Oracle Database server.
When a network session is established, Oracle Net Services acts as the data courier for both the client application and the database. It is responsible for establishing and maintaining the connection between the client application and the database, as well as exchanging messages between them.
Oracle Net Services supports a variety of connection types to connect to an Autonomous Database instance, including:
JDBC Thin Driver: for Java applications, the JDBC Thin Driver is a pure Java driver. Many applications, including Oracle SQL Developer support JDBC Thin Driver connections.
JDBC OCI: which is used by Java language applications. JDBC OCI adds a layer over Oracle Call Interface for Java applications. The Oracle SQLcl command-line interface uses JDBC OCI.
Oracle Call Interface (OCI): used by many applications written in C language. Examples that use Oracle Call Interface include Oracle utilities such as Oracle SQL*Plus, SQL*Loader, and Oracle Data Pump.
ODBC Drivers: used by applications running on Microsoft Windows, that are layered over Oracle Call Interface (OCI).
Third-party products and custom applications may use any of these connection types.
For detailed instructions please visit the oracle documents sit by clicking on the link below.