--在id上建立索引
--具體可以看執行計畫
SET SHOWPLAN_TEXT ON
select a.*
from a join b on a.id=b.id-----------------------------------------------------------------------
select *
from a
where id in
(
select id from b
)
-----------------------------------------------------------------------
--具體可以看執行計畫
SET SHOWPLAN_TEXT ON
select a.*
from a join b on a.id=b.id-----------------------------------------------------------------------
select *
from a
where id in
(
select id from b
)
-----------------------------------------------------------------------
SET SHOWPLAN_TEXT ON
这个设置有什么用?