SELECT B.OWNER,B.TABLE_NAME,ROUND(TABLE_USED_PAGES(B.OWNER,B.TABLE_NAME)*(PAGE/1024)/1024/1024,2) "GB",TABLE_ROWCOUNT(B.OWNER,B.TABLE_NAME) "TABLE_ROWS" FROM (SELECT A.OWNER,A.TABLE_NAME FROM ALL_TABLES A WHERE A.TABLE_NAME NOT LIKE 'CTI%' AND A.TABLE_NAME NOT LIKE 'SREF_CON_TAB%' AND A.TABLE_NAME NOT LIKE 'BM%' ) B ORDER BY 3 DESC,1,2;
可以使用TABLE_USED_SPACE和USER_USED_SPACE函数
例：
查看 SYSDBA 用户的所占用的大小：
SELECT USER_USED_SPACE ('SYSDBA') * PAGE()/1024.0/1024.0/1024.0 GB;
查看 SYSOJBECTS 表的所占用的大小：
SELECT TABLE_USED_SPACE ('SYS','SYSOBJECTS') *PAGE()/1024.0/1024.0/1024.0 GB ;