Oracle DB - Check tablespaces usage

 Tablespaces and datafiles usage:

select
    DTFIL.tablespace_name, DTFIL.file_name,
    ROUND(DTFIL.bytes/power(1024,2),2) USED_MB,
    DTFIL.autoextensible,
    Round(DTFIL.maxbytes/power(1024,3), 2) Maxsize_GB,
    Round((DTFIL.bytes / DTFIL.maxbytes)*100, 2) USED,
    round((DTFIL.increment_by * TBSP.block_size)/power(1024,2), 2) step_MB,
    DTFIL.increment_by
from
    dba_data_files DTFIL join dba_tablespaces TBSP on DTFIL.TABLESPACE_NAME = TBSP.TABLESPACE_NAME
order by DTFIL.tablespace_name, DTFIL.file_name;

Tablespaces usage, including datafiles:

select
    DTFIL.tablespace_name,
    Round((sum(DTFIL.bytes) / sum(DTFIL.maxbytes))*100, 2) USED
from
    dba_data_files DTFIL join dba_tablespaces TBSP on DTFIL.TABLESPACE_NAME = TBSP.TABLESPACE_NAME
group by DTFIL.tablespace_name
order by 2 desc;

Tablespaces usage acording with actual allocated space:

-- Work tablespaces
SELECT
       a.tablespace_name AS tablespace_name,
       (100 - round((nvl(b.bytes_free, 0) / a.bytes_alloc)* 100)) percent_used,
       (100 - round((nvl(b.bytes_free, 0) / a.bytes_alloc)* 100, 2)) pct_used,
       round(a.bytes_alloc / 1024/ 1024,2) allocated,
       round((a.bytes_alloc - nvl(b.bytes_free, 0)) / 1024/ 1024,2) used,      
       round(nvl(b.bytes_free, 0) / 1024/ 1024,2) free,
       a.datafiles
from (select
        f.tablespace_name,
        sum(f.bytes) bytes_alloc,
        sum(decode(f.autoextensible, 'yes', f.maxbytes, 'N0',f.bytes)) maxbytes,
        count(1) datafiles
      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
 
-- TEMP Tablespaces
select
    t.tablespace_name,
    t.percent_used,
    t.pct_used,
    t.allocated,
    t.used,
    t.free,
    f.datafiles
from
    (select
        h.tablespace_name as tablespace_name,
        (100 - round((sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / sum(h.bytes_used + h.bytes_free))* 100)) percent_used,
        (100 - round((sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / sum(h.bytes_used + h.bytes_free))* 100,2)) pct_used,
        round(sum(h.bytes_free + h.bytes_used) / 1048576,2) allocated,
        round(sum(nvl(p.bytes_used, 0))/ 1048576,2) used,
        round(sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / 1048576,2) free
    from
        sys.gv_$TEMP_SPACE_HEADER h,
        sys.gv_$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 ) t,
    (select tablespace_name, count(1) datafiles from dba_temp_files group by tablespace_name ) f
where
    t.tablespace_name = f.tablespace_name
ORDER BY 3 desc