This is a list of the tables in used in Confluence as of version 1.4.2:
If any of these tables in exist in other oracle schemas in the "same database", those tables will not be created, impairing bits of Confluence functionality that depend on those table(s).
The bug is tied to this hibernate SchemaUpdate bug:
This problem also affects PostgreSQL.
This issue only occurs if the database user you are connecting to Oracle with has permission to view all tables across the database, not just those that relate to its own schema. You need to ensure you have followed all the steps in the Database Setup for Oracle document. The relevant ones here are the local all objects view, and ensuring that 'select any table' is not granted. However, all steps in that document need to be followed to avoid running into other issues down the track.