I am running ArcCatalog 10.3.1 and have a direct connection to an Oracle database. Some of the tables are registered with SDE and some are not. In other Oracle instances I am able to see all the tables whether they're registered or not. I can see all the tables in Toad, but not Catalog. I've confirmed that they have a public role assigned to them. We have other Oracle instances and can see all their tables in Catalog. Just not this instance.