SELECT a.tablespace_name "表空间名", total "表空间大小", free "表空间剩余大小", ( total - free ) "表空间使用大小", Round(( total - free ) / total, 4) * 100 "使用率 %" FROM (SELECT tablespace_name, Sum(bytes) free FROM DBA_FREE_SPACE GROUP BY tablespace_name) a, (SELECT tablespace_name, Sum(bytes) total FROM DBA_DATA_FILES GROUP BY tablespace_name) b WHERE a.tablespace_name = b.tablespace_name
http://www.cnblogs.com/xwdreamer/p/3511047.html