How to check Tablespace Space in MB

 column "Tablespace" format a13
 column "Used MB"    format 99,999,999
 column "Free MB"    format 99,999,999
 column "Total MB"   format 99,999,999
 select fs.tablespace_name  "Tablespace", (df.totalspace - fs.freespace) "Used MB",
 fs.freespace  "Free MB", df.totalspace "Total MB", round(100 * (fs.freespace / df.totalspace)) "Pct.  Free"  from (select tablespace_name, round(sum(bytes) / 1048576) TotalSpace
 from dba_data_files group by tablespace_name ) df, (select tablespace_name, round(sum(bytes) /  1048576) FreeSpace from dba_free_space group by tablespace_name) fs where df.tablespace_name  =  fs.tablespace_name;

Tablespace        Used MB     Free MB      Total MB               Pct. Free
------------- ----------- ----------- ----------- -------------------------------------
SYSAUX              1,191          857                2,048                     42
UNDOTBS1          70              5,050             5,120                     99
USERS                  10,218       20,502           30,720                    67
SYSTEM               914            1,134             2,048                      55
UNDOTBS2          71              5,049             5,120                      99


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