#一定要union all with t1 as( select cid, start_time dt, 1 uv from play_record_tb union all select cid, end_time dt, -1 uv from play_record_tb ), t2 as( select cid, sum(uv)over(partition by cid order by dt asc ,uv desc) sum_uv from t1 ) select cid, max(sum_uv) sum_peak_uv from t2 group by cid o...