How to check datafiles and autoextend in Oracle

Every datafile with its current size, whether autoextend is on, the max size it can reach, and the growth increment.

SELECT file_id,
       tablespace_name,
       file_name,
       ROUND(bytes/1024/1024)    AS size_mb,
       autoextensible,
       ROUND(maxbytes/1024/1024) AS max_mb,
       increment_by
FROM   dba_data_files
ORDER  BY tablespace_name, file_id;