DBA TABLE TO KNOW THE SPACE OCCUPIED BY OBJECT

select sum(bytes/1024/1024/1024)||'$'||file_name from dba_data_files group by file_name;
 
  SELECT username,profile,default_tablespace,temporary_tablespace FROM dba_users;

  SELECT SUM (bytes) / 1024 / 1024 / 1024 AS GB FROM dba_data_files;
 
  SELECT SUM (bytes) / 1024 / 1024 / 1024 AS GB FROM dba_segments;

 select SEGMENT_NAME, SUM (bytes) / 1024 / 1024 / 1024 AS GB from dba_segments WHERE UPPER(segment_name) LIKE 'MISO_CAT%' AND SEGMENT_TYPE ='TABLE'  GROUP BY SEGMENT_NAME ORDER BY 2 DESC;--SEGMENT_NAME IS OBJECT NAME