Script to calculate space usage at the database level.

Question

Hi,
Can someone provide me a script to calculate the Total space, Used space and Free space for all tablespaces within a database??
I have been trying to use the below combinations in my queries and both provide different results..
1) dba_data_files & dba_free_space
select t.tablespace, t.totalspace as " Totalspace(MB)", round((t.totalspace-fs.freespace),2) as "Used Space(MB)", fs.freespace as "Freespace(MB)", round(((t.totalspace-fs.freespace)/t.totalspace)*100,2) as "% Used", round((fs.freespace/t.totalspace)*100,2) as "% Free" from (select round(sum(d.bytes)/(1024*1024)) as totalspace, d.tablespace_name tablespace from dba_data_files d group by d.tablespace_name) t, (select round(sum(f.bytes)/(1024*1024)) as freespace, f.tablespace_name tablespace from dba_free_space f group by f.tablespace_name) fs where t.tablespace=fs.tablespace order by t.tablespace;
2) dba_extents & dba_free_space
select t.tablespace, t.totalspace as " Totalspace(MB)", round((t.totalspace-fs.freespace),2) as "Used Space(MB)", fs.freespace as "Freespace(MB)", round(((t.totalspace-fs.freespace)/t.totalspace)*100,2) as "% Used", round((fs.freespace/t.totalspace)*100,2) as "% Free" from (select round(sum(d.bytes)/(1024*1024)) as totalspace, d.tablespace_name tablespace from dba_extents d group by d.tablespace_name) t, (select round(sum(f.bytes)/(1024*1024)) as freespace, f.tablespace_name tablespace from dba_free_space f group by f.tablespace_name) fs where t.tablespace=fs.tablespace order by t.tablespace;
Thanks in advance,
regards,
Arul S

Answer 1

-- check the total,used and free space in tablespaces
select     a.TABLESPACE_NAME,
     a.BYTES MB_total,
     b.BYTES MB_free,
     b.largest,
     a.BYTES-b.BYTES MB_used,
     round(((a.BYTES-b.BYTES)/a.BYTES)*100,2) percent_used
from
          select      TABLESPACE_NAME,
               sum(BYTES)/1048576 BYTES
          from      dba_data_files
          group      by TABLESPACE_NAME
     a,
          select      TABLESPACE_NAME,
               sum(BYTES)/1048576 BYTES ,
               max(BYTES)/1048576 largest
          from      dba_free_space
          group      by TABLESPACE_NAME
     b
where      a.TABLESPACE_NAME=b.TABLESPACE_NAME
order      by ((a.BYTES-b.BYTES)/a.BYTES) desc;
Regards
Asif Kabir