mysql filesort 优化

简历索引
ALTER TABLE `tb_lxpay_order` ADD INDEX idx_card_sort ( `open_id`,`create_time` );


强制使用索引


SELECT a.order_id orderId,a.out_trade_no outTradeNo,a.card_no cardNo,rate,rate_price ratePrice,add_account addAccount, card_money cardMoney,result_msg resultMsg,result_code resultCode,DATE_FORMAT(a.create_time,'%Y-%m-%d %H:%i:%s') as createTime,DATE_FORMAT(a.update_time,'%Y-%m-%d %H:%i:%s') as updateTime,a.statuses,up_price upPrice,a.open_id openId,jobnum,username,canteenname,company_no companyNo,b.mch_id mchid
            from tb_card_order a use index(idx_card_sort) LEFT JOIN    tb_weixin_order b  on a.out_trade_no=b.out_trade_no 
            where   (a.statuses='1' or a.statuses='2' or a.statuses='3') and a.card_no= '1234'   order by a.create_time DESC 

 from tb_card_order a use index(idx_card_sort) LEFT JOIN    tb_weixin_order b  on a.out_trade_no=b.out_trade_no 
            where