Oracle Error Message
ORA-12056: invalid REFRESH method
Reason for the Error
The NEVER REFRESH option may not be used under the following conditions:
* The materialized view is updatable
* The materialized view refreshes ON COMMIT
* Automatic refresh options are specified
Solution
For updatable materialized views, reissue the SQL command using REFRESH FORCE, REFRESH FAST, or REFRESH COMPLETE. For read-only materialized views, reissue the SQL command using ON DEMAND.