Database/Schema/Tablespace sizes

Database size:-

select sum(bytes)/1024/1024 from dba_data_files;

Schema size:-

select owner,segment_name,segment_type, bytes

from dba_segments

order by owner,segment_type;

SELECT tablespace_name,owner,sum(bytes)/1024/1024 AS total_size_mb FROM dba_segments WHERE owner = 'schema_name';

select owner, segment_type, sum(bytes) "Bytes"

from dba_segments

group by owner, segment_type;

select segment_name,segment_type,bytes/1024/1024 MB from dba_segments

where segment_type='TABLE' and segment_name='';

Tablespace sizes :-

select tablespace_name, owner, SUM(BYTES)/1047685/1024 SIZE_GB

from dba_segments

group by rollup(owner,tablespace_name);