Each Schema's Used Space

To check space used by each user schema, you can use the following Query.

/* Space used by each Schema */
select substr(owner,1,16) owner, substr(tablespace_name,1,26) tablespace_name,substr(segment_type,1,10) segment_type,sum(bytes/(1024*1024)) Mbytes,
sum(blocks) blocks from sys.dba_extents
where owner not in ('SYS','SYSTEM','SYSADMIN','SYSMAN','SH','DBSNMP','CTXSYS','EXFSYS','WMSYS','XDB','TSMSYS','MDSYS','OLAPSYS','OUTLN',
'ORDSYS','PM','OE','SCOTT','IX','HR','DMSYS')
group by substr(owner,1,16),substr(tablespace_name,1,26),substr(segment_type,1,10)
order by 1,2,3