I've got two tables, parcels and permits. I'd like to display permits on a map without having to copy the geometry data from parcels. Is there a way to create a join in Mapviewer? Do I have to create a view?
Creating a view joining parcels and permits is advisable. You can use it in other situations as well (data querying etc.).
See a sample of doing so in Joining spatial and not spatial table in oracle.