I have an SQL Server 2008 Express Edition and added an Oracle DB as a linked server with the OraOLEDB.Oracle provider. The connection works but I can only see the views from the Oracle server, no tables, and no materialized views.
I can SELECT * on the visible views, so there doesn’t seem to be an obvious problem with the linking.
Problem solved: I was looking for the tables and materialized views in SQL Management Studio in the Object Explorer tree, which only showed me the “normal” views. I opened the Object Explorer Details view (F7) and there they all were: tables and views. The materialized views are also displayed under tables.