System Catalog Tables v12
The system catalog tables contain definitions of database objects that are available to Advanced Server; the layout of the system tables is subject to change. If you are writing an application that depends on information stored in the system tables, it would be prudent to use an existing catalog view, or create a catalog view to isolate the application from changes to the system table.
For detailed information about the system catalog tables, see the Database Compatibility for Oracle Developers Catalog Views Guide, available at:
https://www.enterprisedb.com/docs/epas/latest/epas_compat_cat_views/