Få kuvert, dvs överlappande tidsintervall

Prova den här också. Jag testade det så gott jag kunde, jag tror att det täcker alla möjligheter, inklusive sammansmältning av angränsande intervall (10:15 till 10:30 och 10:30 till 10:40 kombineras till ett enda intervall, 10:15 till 10:40 ). Den ska också vara ganska snabb, den använder inte mycket.

with m as
        (
         select ip_address, start_time,
                   max(stop_time) over (partition by ip_address order by start_time 
                             rows between unbounded preceding and 1 preceding) as m_time
         from ip_sessions
         union all
         select ip_address, NULL, max(stop_time) from ip_sessions group by ip_address
        ),
     n as
        (
         select ip_address, start_time, m_time 
         from m 
         where start_time > m_time or start_time is null or m_time is null
        ),
     f as
        (
         select ip_address, start_time,
            lead(m_time) over (partition by ip_address order by start_time) as stop_time
         from n
        )
select * from f where start_time is not null
/