Small query to list Oracle tablespaces, that are in backup mode:
SELECT d.tablespace_name, b.TIME
FROM dba_data_files d, v$backup b
WHERE
d.file_id = b.FILE#
AND b.STATUS = 'ACTIVE' ;
FROM dba_data_files d, v$backup b
WHERE
d.file_id = b.FILE#
AND b.STATUS = 'ACTIVE' ;
