Internal materialized views are indexed by its Primary Key. So, if you have not defined a PK define one on the table. If it is external materialization, modify the DDL that you used to create the external materialization views in the database such that they have indexes on them.
But most importantly you need to figure out, when you say performance problems what they are? Define your usecase what you are doing, the query and query plan and we can suggest any improvements. Materialization does not mean it will speed up the process, it also depends on what you are materializing, and your are utilizing it.
Internal materialization will also create indexes for unique and index (including function based index) metadata on the view.
Thanks Ramesh and Steven,
How do i do the query plan in the Teiid VDB?
The simplest is if you are using client tool like SquirreL, execute
SET SHOWPLAN DEBUG
then look in the server.log