How to delete tablespaces that contain materialized views in Oracle

The tablespace deleted today contains materialized view error, ORA-23515: materialized view and/or their indexes exist in the tablespace
It seems that it is necessary to delete the materialized view and perform the delete operation. Because the data is too big and has not been completed for half a day, it is canceled. Check the Internet for another method, delete the user, and specify the cascade parameter, in this way, you can

I tried it.
Drop user user_name cascade;
Deleting a materialized view is faster than deleting a materialized view.

Summary: how to delete tablespaces that contain materialized views
1. Delete the user of the materialized view first
Drop user user_name cascade;
Delete a tablespace
Drop tablespace tablespace_name including contents and datafiles;

2. Delete the materialized view and then the tablespace.
Drop materialized view view_name;
Delete the tablespace.
Drop tablespace tablespace_name including contents and datafiles;

It doesn't matter if the data size is small. If the data size is large, we recommend that you use the first method.