Do you have a service layer on top of your Oracle database doing the inserts / updates? If so, your service layer can be pushing updates via Web Sockets.
If someone else is doing the inserts from another application where you are just sharing a database, you need to find out if Oracle DB has a way to notify you of inserts, I doubt it though. Otherwise that other application needs to notify you that it made an insert / update.
If you're looking for Web Sockets solutions, I usually use VertX for web sockets, Spring MVC has that option as well and I'm pretty sure there are other options as well.