帮忙优化一下这个 sql： select dt ukey user_type is_pv as flagpage_typesource from gamelivedwd_huya_taskcenter_detail_with_dim_d_i where dt=$tdatestringyyyy-MM-dd and event_name in 任务中心曝光 group by dtukeyuse

尝试优化的 SQL：

SELECT dt, ukey, user_type, flag, page_type, source FROM ( SELECT dt, ukey, user_type, 'is_pv' AS flag, page_type, source FROM gamelive.dwd_huya_taskcenter_detail_with_dim_d_i WHERE dt = '${tdate?string('yyyy-MM-dd')}' AND event_name = '任务中心曝光' UNION ALL SELECT dt, ukey, user_type, 'is_sign' AS flag, page_type, source FROM gamelive.dwd_huya_taskcenter_detail_with_dim_d_i WHERE dt = '${tdate?string('yyyy-MM-dd')}' AND eventid = 'usr/click/signin/taskcenter' ) AS tmp GROUP BY dt, ukey, user_type, flag, page_type, source

优化说明：

1. 将两个子查询的结果使用 UNION ALL 连接，避免使用 GROUP BY 合并结果集时的重复计算；
2. 在 UNION ALL 外层包裹一个 GROUP BY，避免结果集出现重复行。