1数据量比较小的表放在前边：

select n.applyid from re_newafterloan n inner join re_apply a on a.applyid=n.applyid;

select n.applyid from re_apply a inner join re_newafterloan n on a.applyid=n.applyid;

2整合sql,减少数据库的访问次数

select count(*) from re_bizcodecfg b where b.bizcodetype='zhonghang' ; select count(*) from re_bizcodecfg b where b.bizcodetype='signingModel' ; 整合后 select count(decode(bizcodetype,'zhonghang','x',null)) as avic,count(decode(bizcodetype,'signingModel','y',null)) as models from re_bizcodecfg