Can u explain the query?

Question

select file_name,
ceil( (nvl(hwm,1)*8192)/1024/1024 ) possible,
ceil( blocks*8192/1024/1024) current,
ceil( blocks*8192/1024/1024) -
ceil( (nvl(hwm,1)*8192)/1024/1024 ) saving
from dba_data_files a,
( select file_id, max(block_id+blocks-1) hwm
from dba_extents
group by file_id ) b
where a.file_id = b.file_id(+) and a.tablespace_name = '&tsname'
can u please explain the query and wat does ceil mean ??

Answer 1

can u please explain the query and wat does ceil mean ??http://www.psoug.org/reference/number_func.html
SQL> SELECT CEIL(12345.67) FROM dual;
CEIL(12345.67)
         12346
SQL> SELECT CEIL(12345.99) FROM dual;
CEIL(12345.99)
         12346
SQL> SELECT CEIL(12345.00) FROM dual;
CEIL(12345.00)
         12345
SQL>