这条语句为何这么慢。。。（stuff 有4K条记录,datetimer 有5W条记录）没建索引
select * from
(select bianhao from stuff where loss=0 and flid=38) a
,(select * from datetimer where rq> = '2007-06-01 ' and rq <= '2007-06-28 ') b
where a.bianhao=b.bianhao
如果要建索引应该怎么创建好点。
[解决办法]
select a.bianhao,b.* from stuff a,datetimer,b where a.bianhao=b.bianhao and a.loss=0 and a.flid=38 and b.rq> = '2007-06-01 ' and b.rq <= '2007-06-28 '
[解决办法]
stuff 在 loss,flid 建联合索引
datetimer 在rq上建立索引
select a.bianhao,b.* from stuff a inner join datetimer b on a.bianhao=b.bianhao
where a.loss=0 and b.flid=38 and b.rq> = '2007-06-01 ' and b.rq <= '2007-06-28 '
