Find peaks of data - sql

Question

So I have a table Integrations.
Inte
Start Date
End Date
Total_Duration
INT1
1/7/2021 7:16:00
1/7/2021 9:22:00
02:06:00
INt2
2/7/2021 3:48:00
2/7/2021 5:10:00
01:22:00
Output I need:
Running Time
No of Inte.
1/7/2021 7:00:00
1
1/7/2021 8:00:00
1
1/7/2021 9:00:00
1
2/7/2021 4:00:00
1
2/7/2021 5:00:00
1
Basically it want to plot the peak hour when most Integrations were running.
Sql query I wrote:
select time, sum(value) as No_of_Inte
from(
select round(Start_Date, 'HH24') as time, count(*) as value
from Integrations
group by Start_Date
)
group by time
order by time asc
But this does not consider Total Duration.
Output :
Running Time
No of Inte.
1/7/2021 7:00:00
1
2/7/2021 4:00:00
1
Also, new Integrations are added every day.

Answer 1

This can be done using a recursive query. First create the test data
CREATE TABLE integrations (inte,start_date, end_date)
AS
(
SELECT 'INT1', TO_DATE('1/7/2021 7:16:00','DD/MM/YYYY HH24:MI:SS'), TO_DATE('1/7/2021 9:22:00','DD/MM/YYYY HH24:MI:SS') FROM dual UNION ALL
SELECT 'INT2', TO_DATE('2/7/2021 3:48:00','DD/MM/YYYY HH24:MI:SS'), TO_DATE('2/7/2021 5:10:00','DD/MM/YYYY HH24:MI:SS') FROM dual
);
Now use a recursive query to loop through the hours between start and end date. Then group by hour to get the correct counts per hour.
WITH row_per_hours (id, run_hour, end_date) AS
(
SELECT inte,
TRUNC(start_date,'HH24'),
end_date
FROM integrations
UNION ALL
SELECT id,
run_hour + INTERVAL '1' HOUR,
end_date
FROM row_per_hours
WHERE run_hour + INTERVAL '1' HOUR < end_date
)
SELECT TO_CHAR(run_hour,'DD/MM/YYYY HH24:MI:SS') as running_time,
COUNT(id) as integration_count
FROM row_per_hours
GROUP BY TO_CHAR(run_hour,'DD/MM/YYYY HH24:MI:SS') ORDER BY 1;
RUNNING_TIME INTEGRATION_COUNT
------------------- -----------------
01/07/2021 07:00:00 1
01/07/2021 08:00:00 1
01/07/2021 09:00:00 1
02/07/2021 03:00:00 1
02/07/2021 04:00:00 1
02/07/2021 05:00:00 1

Answer 2

For 12C and above:
You may use lateral join to generate required number of rows per each interval. Since it looks like you need some rounding of dates towards neares hour, I've added round instead of trunc. Or is there any other reason for the first interval is treating 7:00 as inclusion?.
with a(Inte, start_dt, end_dt) as (
select
'INT1'
, to_date('1/7/2021 07:16:00', 'dd/mm/yyyy hh24:mi:ss')
, to_date('1/7/2021 09:22:00', 'dd/mm/yyyy hh24:mi:ss')
from dual union all
select
'INt2'
, to_date('2/7/2021 03:48:00', 'dd/mm/yyyy hh24:mi:ss')
, to_date('2/7/2021 05:10:00', 'dd/mm/yyyy hh24:mi:ss')
from dual
)
select /*+ gather_plan_statistics */
b.hour_
, count(1) as int_cnt
from a
outer apply (
select
round(a.start_dt + numtodsinterval(level - 1, 'HOUR'), 'hh24') as hour_
from dual
connect by round(start_dt, 'hh24') + numtodsinterval(level - 1, 'HOUR') <= trunc(end_dt, 'hh24')
) b
group by b.hour_
order by 1
HOUR_ | INT_CNT
:------------------ | ------:
2021-07-01 07:00:00 | 1
2021-07-01 08:00:00 | 1
2021-07-01 09:00:00 | 1
2021-07-02 04:00:00 | 1
2021-07-02 05:00:00 | 1
db<>fiddle here