1、查看所有隐藏参数

select i.ksppinm name,i.ksppdesc description,cv.ksppstvl value,cv.ksppstdf isdefault,decode(bitand(cv.ksppstvf,7),1,'modified',4,'system_mod','false') ismodified,2),2,'true','false') isadjusted
	from sys.x$ksppi i,sys.x$ksppcv cv
 where i.inst_id = userenv('instance')
	 and cv.inst_id = userenv('instance')
	 and i.indx = cv.indx
	 and i.ksppinm like '/_%' escape '/'
 order by replace(i.ksppinm,'_','');

select ksppinm,ksppstvl,ksppdesc
	from x$ksppi x,x$ksppcv y
 where x.indx = y.indx
	 and translate(ksppinm,'#') like '#%';

select ksppinm,x$ksppcv y
 where x.indx = y.indx
	 and ksppinm = '_db_block_hash_buckets';