请教优化问题 高手请进!
我写了一个查询语句如下:
select FreightOrder.Fromsitecode fromwarehouse,
FreightOrder.Fromsitename FromWHName,
FreightOrder.Tositecode toWarehouse,
FreightOrder.Tositename TOWHName,
packline.ordertype,
item.uniquekey item,
sysdate statisticdate,
facility.ownership,
packline.packqty,
packline.packqty * parameter.parvalue inventoryvalue,
facility.category
from
itaitem item,
BOAPARGRP ParGroup,
BOABOPARAM parameter,
FMPFRGTORD FreightOrder,
WHAMPACLST MainPackList,
WHAMPACLIN packline,
loafacilit facility
where
item.Uniquekey = ParGroup.Parentbo and
parameter.parentgroup = parGroup.Uniquekey and
MainPackList.Foid = FreightOrder.Pid and
packline.parentlist = mainpackList.Uniquekey
其中itaitem, BOAPARGRP,BOABOPARAM都是大表(100万),我希望的执行计划应先连接小表,在连接大表。但执行计划总先连接三个大表。 如何改变执行计划的顺序?