oracl 和db2 常用语法比较： 1、取前N条记录 Oracle：Select * from TableName where rownum <= N; DB2：Select * from TableName fetch first N rows only; 2、取得系统日期 Oracle：Select sysdate from dual; DB2：Select current timestamp from sysibm.sysdummy1; 3、空值转换 Oracle：Select

本文给大家分享一个oracle查看表空间已分配和未分配空间的语句，大家参考使用吧

代码如下:selectb.tablespace_name,mbytes_alloc,mbytes_free from(select round(sum(bytes)/1024/1024) mbytes_free,tablespace_name  from dba_free_space  group by tablespace_name) a, (select round(sum(bytes)/1024/1024) mbytes_alloc,tablespace_name  from dba_da