left join运行了1分1秒，inner join运行了不到1秒

刚才用了20万行两个表关联查询，运行1000次，发现效果差距很大。
left join用了1分1秒；
inner join用了不到1秒；

		From 
			fittings As Fit inner Join FitRunType As FRT On FRT.sID=FIT.sRunType 
			INNER join 
			(	select * from FitStore
					where sProperty1 like @sCode+'%' Or sProperty2 like @sCode+'%' Or sProperty3 like @sCode+'%'
			) As ST On FIT.sID=ST.sItemID