Find out free space on tablespace

Question

Our application has failed a few times because an \'ORA-01536: space quota exceeded for tablespace\', and we would like to be able to prevent this by checking regularly the

Answer 1

column pct_free format 999.99
select
     used.tablespace_name,
     (reserv.maxbytes - used.bytes)*100/reserv.maxbytes pct_free,
     used.bytes/1024/1024/1024 used_gb,
     reserv.maxbytes/1024/1024/1024 maxgb,
     reserv.bytes/1024/1024/1024 gb,
     (reserv.maxbytes - used.bytes)/1024/1024/1024 "max free bytes",
     reserv.datafiles
from
    (select tablespace_name, count(1) datafiles, sum(greatest(maxbytes,bytes)) maxbytes, sum(bytes) bytes from dba_data_files group by tablespace_name) reserv,
    (select tablespace_name, sum(bytes) bytes from dba_segments group by tablespace_name) used
where used.tablespace_name = reserv.tablespace_name
order by 2
/

Answer 2

You can use a script called tablespaces.sh inside this helpful bundle: http://dba-tips.blogspot.com/2014/02/oracle-database-administration-scripts.html

Answer 3

Unless I'm mistaken, the above code does not take unallocated space into account, so if you really want to know when you'll hit a hard limit, you should use maxbytes.

I think the code below does that. It calculates free space as "freespace" + unallocated space.

select 
     free.tablespace_name,
     free.bytes,
     reserv.maxbytes,
     reserv.bytes,
     reserv.maxbytes - reserv.bytes + free.bytes "max free bytes",
     reserv.datafiles
from
    (select tablespace_name, count(1) datafiles, sum(maxbytes) maxbytes, sum(bytes) bytes from dba_data_files group by tablespace_name) reserv,
    (select tablespace_name, sum(bytes) bytes from dba_free_space group by tablespace_name) free
where free.tablespace_name = reserv.tablespace_name;

Answer 4

A much more accurate SQL STATEMENT

SELECT  a.tablespace_name,
    ROUND (((c.BYTES - NVL (b.BYTES, 0)) / c.BYTES) * 100,2) percentage_used,
    c.BYTES / 1024 / 1024 space_allocated,
    ROUND (c.BYTES / 1024 / 1024 - NVL (b.BYTES, 0) / 1024 / 1024,2) space_used,
    ROUND (NVL (b.BYTES, 0) / 1024 / 1024, 2) space_free, 
    c.DATAFILES
  FROM dba_tablespaces a,
       (    SELECT   tablespace_name, 
                  SUM (BYTES) BYTES
           FROM   dba_free_space
       GROUP BY   tablespace_name
       ) b,
      (    SELECT   COUNT (1) DATAFILES, 
                  SUM (BYTES) BYTES, 
                  tablespace_name
           FROM   dba_data_files
       GROUP BY   tablespace_name
    ) c
  WHERE b.tablespace_name(+) = a.tablespace_name 
    AND c.tablespace_name(+) = a.tablespace_name
ORDER BY NVL (((c.BYTES - NVL (b.BYTES, 0)) / c.BYTES), 0) DESC;

Answer 5

You can also get a rough idea of table space usage by looking at the size of the files on your disk.

My DB is created with max extents, and each dbf file can only grow to 32gigs - so when the last one reaches 32gigs, you know you're about to run out of room and need to add another.

Answer 6

Here is a query used by Oracle SQL Developer in its Tablespaces view

select a.tablespace_name as "Tablespace Name",
       round(a.bytes_alloc / 1024 / 1024) "Allocated (MB)",
       round(nvl(b.bytes_free, 0) / 1024 / 1024) "Free (MB)",
       round((a.bytes_alloc - nvl(b.bytes_free, 0)) / 1024 / 1024) "Used (MB)",
       round((nvl(b.bytes_free, 0) / a.bytes_alloc) * 100) "% Free",
       100 - round((nvl(b.bytes_free, 0) / a.bytes_alloc) * 100) "% Used",
       round(maxbytes/1024 / 1024) "Max. Bytes (MB)"
from  ( select  f.tablespace_name,
               sum(f.bytes) bytes_alloc,
               sum(decode(f.autoextensible, 'YES',f.maxbytes,'NO', f.bytes)) maxbytes
        from dba_data_files f
        group by tablespace_name) a,
      ( select  f.tablespace_name,
               sum(f.bytes)  bytes_free
        from dba_free_space f
        group by tablespace_name) b
where a.tablespace_name = b.tablespace_name (+)
union all
select 
       h.tablespace_name as tablespace_name,
       round(sum(h.bytes_free + h.bytes_used) / 1048576) megs_alloc,
       round(sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / 1048576) megs_free,
       round(sum(nvl(p.bytes_used, 0))/ 1048576) megs_used,
       round((sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / sum(h.bytes_used + h.bytes_free)) * 100) Pct_Free,
       100 - round((sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / sum(h.bytes_used + h.bytes_free)) * 100) pct_used,
       round(sum(f.maxbytes) / 1048576) max
from   sys.v_$TEMP_SPACE_HEADER h, sys.v_$Temp_extent_pool p, dba_temp_files f
where  p.file_id(+) = h.file_id
and    p.tablespace_name(+) = h.tablespace_name
and    f.file_id = h.file_id
and    f.tablespace_name = h.tablespace_name
group by h.tablespace_name
ORDER BY 2;