Find max concurrent inbound calls in CDR's

--on newer cdr's use tstzrange instead of tsrange
--this query can take a long time on systems with a lot of records.
--needs optimization (esp filtering the date)
WITH timeslots AS (
        SELECT * FROM (
        SELECT
                direction, tsrange(timepoint, lead(timepoint) OVER (ORDER BY timepoint)),
                lead(timepoint) OVER (ORDER BY timepoint)
                FROM (
                        SELECT
                                direction, unnest(ARRAY["start_stamp", "end_stamp"]) as timepoint
                                FROM
                                v_xml_cdr
                                WHERE "direction" = 'inbound' AND (CAST("start_stamp" AS text) LIKE '%2021-11%' OR CAST("end_stamp" AS text) LIKE '%2021-11%')
                                        AND "domain_uuid" = 'PASTE_UUID_HERE' AND ("hangup_cause" != 'NO_ROUTE_DESTINATION' OR "sip_hangup_disposition" != 'send_refuse')
                                ORDER BY timepoint
                        ) s
            )s  WHERE lead IS NOT NULL
)
SELECT
   GREATEST(MAX(start_stamp), lower(tsrange)),
   LEAST(MIN("end_stamp"), upper(tsrange)),
   COUNT(xml_cdr_uuid),
        array_agg(xml_cdr_uuid)
        FROM
        timeslots t
        JOIN v_xml_cdr a
        ON (t.tsrange && tsrange(a.start_stamp, a.end_stamp)) AND a.direction='inbound'
        GROUP BY tsrange
        HAVING cardinality(array_agg(xml_cdr_uuid)) > 1
        ORDER BY COUNT