mysql问题，跪求高手解答

select c.globalUid,c.badge,temp.sumB,temp.sumP from tb_user c,(select a.uid,sum(a.badge) as sumB,IFNULL(sum(b.propertyNum),0) as sumP,sum(a.badge)-IFNULL(sum(b.propertyNum),0) as cha from tb_buyfun_log a left join buyrecord b on a.uid=b.globaluid group by a.uid having cha>500) as temp where uptime>'2009-12-01 00:00:00' and globaluid=temp.uid


谁帮忙优化下这语句，我在电脑上运行后很慢，有时半天都不出来，有时连查询工具都搞起死掉，关也关不了， 各位高手帮忙看下好不？

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SQL code:
select c.globalUid,c.badge,temp.sumB,temp.sumP
from tb_user c,(
select a.uid,sum(a.badge) as sumB,
IFNULL(sum(b.propertyNum),0) as sumP,
sum(a.badge)-IFNULL(sum(b.propertyNum),0) as cha
from tb_buyfun_log a left join buyrecord b on a.uid=b.globaluid
group by a.uid
having cha>500
) as temp
where uptime>'2009-12-01 00:00:00' and globaluid=temp.uid



你这是个笛卡积啊。

贴出你的
show index from tb_user
show index from tb_buyfun_log
show index from buyrecord
以及
explain select c.globalUid,c.badge,temp.sumB,temp.sumP
from tb_user c,(
select a.uid,sum(a.badge) as sumB,
IFNULL(sum(b.propertyNum),0) as sumP,
sum(a.badge)-IFNULL(sum(b.propertyNum),0) as cha
from tb_buyfun_log a left join buyrec