I wonder if there is any way to do this via Flow or LogicApps. https://powerapps.microsoft.com/en-us/blog/connecting-to-oracle-database-from-powerapps-flow-and-logic-apps/ indicates that you can use an On Prem data gateway with your Oracle database to expose it to Flow / LogicApps, and using either of those tools, you can create a REST web service.... then it would just be a matter of creating a connection in InfoPath to your REST service. I'd probably start with Flow and set up a Flow with an HTTP request trigger - just return some dummy data and make sure you can connect to it in InfoPath and that it works as anticipated in your published form (i.e. - make sure you have a functional proof of concept before adding in the cost of the Oracle setup). Then, once you know that works, you can see about getting the On Prem gateway set up and add an Oracle connection to your Flow (but do note that is a premium connector and I'm not certain what the costs here may be).
Hilary Stoupa
