DB version : 11.2.0.4
OS : Oracle Linux 6.4
I have a DB which is 21 TeraBytes in size as reflected in DBA_DATA_FILES.BYTES . But, the space consumed by objects is much lesser (around 5.5 TB) as shown below from the outpus of DBA_SEGMENTS and DBA_EXTENTS views
But, there is a difference of around 6GB between sum(DBA_SEGMENTS.BYTES) and sum(DBA_EXTENTS.BYTES) . Shouldn't these two views provide the same number ?
SQL> select sum(bytes/1024/1024/1024) bytesGB from dba_Data_Files;
BYTESGB
----------
21447.9961
SQL> select sum(bytes/1024/1024/1024) bytesGB from dba_segments;
BYTESGB
----------
5680.51129
SQL> select sum(bytes/1024/1024/1024) bytesGB from dba_extents;
BYTESGB
----------
5674.91309