V$MVREFRESH displays information about the materialized views currently being refreshed.
Session serial number, which is used to uniquely identify a session's objects. Guarantees that session-level commands are applied to the correct session objects if the session ends with, and another session begins with, the same session ID.
Owner of the materialized view currently being refreshed. The materialized view resides in this user's schema.
Name of the materialized view currently being refreshed
The ID of the container to which the data pertains. Possible values include:
0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data