题解 | 播放量峰值top3高的视频

with t as(
    select cid,start_time as timeu,1 as flag
    from play_record_tb
    union all
    select cid,end_time as timeu,-1 as flag
    from play_record_tb
),

uv as (
    select
    cid,timeu,sum(flag) over(partition by cid order by timeu,flag desc) as time_uv
    from t
)

select
cid,max(time_uv) as max_peak_uv
from uv
group by cid
order by max_peak_uv desc
limit 3;