dbms_stats包的使用误区
SQL> select count(*) from wl; COUNT(*)---------- 29676SQL> delete from wl where rownum<10000;已删除9999行。SQL> commit;提交完成。SQL> select count(*) from wl; ...
x$的系统表
在视图V$fixed_table中可以查到所有的x$表,同时这些表也等于X$KQFTA+X$KQFDT这两个表中X$表的数量。select count(*) from(select kqfdtnam from x$kqfdtunionselect kqftanam from x$KQFTA)select count(*) from V...