GROUP BY overlapping (tsrange) entries

Hi all.
 
I'm trying to count() overlapping entries (timestamp-ranges, tsrange) and have
the following test-data:
 
create table event( id SERIAL PRIMARY KEY, start_time timestamp NOT NULL,
end_timeTIMESTAMP, tsrange TSRANGE NOT NULL ); CREATE INDEX event_range_idx ON
event USING gist(tsrange); -- Populate tsrange in this trigger CREATE OR
REPLACE FUNCTIONevent_update_tf() returns TRIGGER AS $$ BEGIN if NEW.end_time
IS NOT NULL then NEW.tsrange = tsrange(NEW.start_time, NEW.end_time, '[]');
else NEW.tsrange = tsrange(NEW.start_time, null, '[)'); end if; RETURN NEW;
END;$$ LANGUAGE plpgsql; CREATE TRIGGER event_update_t BEFORE INSERT OR UPDATE
ON eventFOR EACH ROW EXECUTE PROCEDURE event_update_tf(); insert into event
(start_time, end_time)values('2015-12-20', NULL) , ('2015-12-20', '2015-12-31')
, ('2015-12-25', '2016-01-01') , ('2015-11-20', '2015-11-24') , ('2016-02-01',
'2016-02-03') , ('2016-02-01', '2016-02-04') , ('2016-02-01', NULL) ; What I'd
like is output like this:

 count
───────
     1
     3
     3
(3 rows)

Something like:
SELECT count(*) FROM event group by (tsrange with &&);
 
PS: In my real query the tsrange and other data is the result of a query
involving multile tables, this is just a simplified example to deal with the
"group by tsquery"
 
Thanks.
 
-- Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
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