数据帝

参数“_sort_elimination_cost_ratio”含义如下（转自http://space.itpub.net/22034023/viewspace-716217）： create table t1 as select * from dba_objects where object_id is not null; alter table t1 add constraint

set lines 200 set pages 100 col KSPPINM for a45 col KSPPSTVL for a10 col KSPPDESC for a80 select x.ksppinm, y.ksppstvl, x.ksppdesc from x$ksppi x , x$kspp