OBIEE 12c (and 11g and 10g before it) supports three primary ways
[https://docs.oracle.com/middleware/1221/biee/BIEMG/deploy_rpd.htm#BIEMG1465] of
connecting to data sources:
1. Native Gateway
[https://docs.oracle.com/middleware/1221/biee/BIEMG/deploy_rpd.htm#BIEMG1179]
, such as OCI for Oracle. This