datafiles

the location of data files

select file_name from dba_data_files;

resize datafile

alter database datafile 'datafile_name' resize 50G;

autoextend and maxsize

ALTER DATABASE datafile 'datafile_name' autoextend ON maxsize 10 G;

add datafile

ALTER TABLESPACE tablespace_name ADD DATAFILE '+DATA' SIZE 100M AUTOEXTEND ON MAXSIZE 10G;

show all the datafiles that as currently associated with taulualueen_nimi tablespace. 

SELECT file_id, file_name, bytes/1024/1024 size_mb
FROM dba_data_files
WHERE tablespace_name = 'Taulualueen_nimi';

renaming or moving oracle files