can i restrict users from access system tables?
I have tried to do it via SEARCH_PATH however v_catalog, v_monitor, v_internal automaticly added to the search_path.
I could be incorrect, but my understanding is that this is not possible - and for good reason.
The system tables include metadata that third-party tools (some that you or your users probably use) need in order operate. It's an important aspect of the interoperability between the Vertica Database and clients.
The system tables do limit their content to the content that the user has access to, however. So the users should only be able to see items that they can make use of, and no more.