SELECT pg_cancel_backend(PID)

SELECT pg_terminate_backend(PID)

SELECT * FROM pg_stat_activity;

SELECT pg_terminate_backend (10841);

create function foo(v_weather varchar(10), v_timeofday varchar(10), v_speed varchar(10),
 v_behavior varchar(10))
 returns setof CUSTOMBEHAVIOR
 as $body$
 begin
 -- run-time error if either of these lines is un-commented
 -- start transaction ISOLATION LEVEL READ COMMITTED;
 -- or, alternatively, set transaction ISOLATION LEVEL READ COMMITTED;
  delete from CUSTOMBEHAVIOR 
  where weather = 'RAIN' and timeofday = 'NIGHT' and speed= '45MPH' ;
 -- if there is no default behavior insert a custom behavior
 if not exists
  (select id from DEFAULTBEHAVIOR where a = 'RAIN' and b = 'NIGHT' and c= '45MPH') then 
  insert into CUSTOMBEHAVIOR
  (weather, timeofday, speed, behavior)
  values
  (v_weather, v_timeofday, v_speed, v_behavior);
 end if;
 return QUERY
 select * from CUSTOMBEHAVIOR where ... ;
 -- commit;
 end
 $body$
 LANGUAGE plpgsql

CREATE FUNCTION foo(v_weather text
   , v_timeofday text
   , v_speed text
   , v_behavior text)
 RETURNS SETOF custombehavior AS
$body$
BEGIN
DELETE FROM custombehavior
WHERE weather = 'RAIN'
AND timeofday = 'NIGHT'
AND speed = '45MPH';
INSERT INTO custombehavior (weather, timeofday, speed, behavior)
SELECT v_weather, v_timeofday, v_speed, v_behavior
WHERE NOT EXISTS (
 SELECT 1 FROM defaultbehavior
 WHERE a = 'RAIN'
 AND b = 'NIGHT'
 AND c = '45MPH'
 );
RETURN QUERY
SELECT * FROM custombehavior WHERE ... ;
END
$body$LANGUAGE plpgsql