Oracle 因為有 Autoextend 這個概念, 所以在空間預算上可以伸延(Auto extent )的空間也是不可忽略的一環 , 以下SQL 可以幫助你找到, 現有空間的大小, 使用率 及最大可以伸延的空間:
select a.tablespace_name, round(a.bytes_alloc / 1024 / 1024, 2) Allocated_Space, round(nvl(b.bytes_free, 0) / 1024 / 1024, 2) Free_Space, round((a.bytes_alloc - nvl(b.bytes_free, 0)) / 1024 / 1024, 2) Used_Space, round((nvl(b.bytes_free, 0) / a.bytes_alloc) * 100,2) Free_Percent, 100 - round((nvl(b.bytes_free, 0) / a.bytes_alloc) * 100,2) Used_Percent, round(maxbytes/1048576,2) "Max(Autoextend Included)" 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 select h.tablespace_name, round(sum(h.bytes_free + h.bytes_used) / 1048576, 2), round(sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / 1048576, 2), round(sum(nvl(p.bytes_used, 0))/ 1048576, 2), round((sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / sum(h.bytes_used + h.bytes_free)) * 100,2), 100 - round((sum((h.bytes_free + h.bytes_used) - nvl(p.bytes_used, 0)) / sum(h.bytes_used + h.bytes_free)) * 100,2), round(max(h.bytes_used + h.bytes_free) / 1048576, 2) from sys.v_$TEMP_SPACE_HEADER h, sys.v_$Temp_extent_pool p where p.file_id(+) = h.file_id and p.tablespace_name(+) = h.tablespace_name group by h.tablespace_name ORDER BY 1;