1.查看隐藏参数
脚本1:
SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc describ
FROM SYS.x$ksppi x, SYS.x$ksppcv y
WHERE x.inst_id = USERENV ('Instance')
AND y.inst_id = USERENV ('Instance')
AND x.indx = y.indx
AND x.ksppinm LIKE '%&par%'脚本2:
select
x.ksppinm name,
y.ksppstvl value,
y.ksppstdf isdefault,
decode(bitand(y.ksppstvf,7),1,'MODIFIED',4,'SYSTEM_MOD','FALSE') ismod,
decode(bitand(y.ksppstvf,2),2,'TRUE','FALSE') isadj
from
sys.x$ksppi x,
sys.x$ksppcv y
where
x.inst_id = userenv('Instance') and
y.inst_id = userenv('Instance') and
x.indx = y.indx and
x.ksppinm like '%_&par%'
order by
translate(x.ksppinm,'_','') 2.Oracle通过一个内部参数_small_table_threshold来定义大表和小表的界限.缺省情况下该参数等于2%的数量,如果表的buffer大小小于这个参数的定义,则oracle认为它是小表,反之为大表.
select (db_cache_size/块size)*0.02 from dual
posted on 2011-06-11 20:44
xrzp 阅读(319)
评论(0) 编辑 收藏 所属分类:
oracle-基础