There are two connection modes to Oracle in our applications:

  1. Oracle Client (OCI)
  2. Direct

When connecting via OCI, we will use information saved in tnsnames.ora configuration file. When connecting directly, that file is ignored.

Authentication mode SYSDBA or SYSOPER should be used very rarely. It's recommended to use standard Oracle users to connect.

Please note that you can choose either SID or Service name when specifying your database.