Postgresql same date record insert - postgresql

Question

I am using a Postgresql 9.5 database. A third party software application is also using this database. I have a Features table. I created an Events table to record Features events.
Features
------------
id name lon lat
1 x 0 10
2 y 15 20
When I create a record in the Features table, my trigger inserts a record into the Events table.
Events
id name date feature_id
1 insert 09.04.2018 14:22:23.065125 1
When I update Features name, lon and lat and save it, the software execution results in 3 update records at same time.
Events
id name date feature_id
1 insert 09.04.2018 14:22:23.065125 1
2 update 09.04.2018 18:15:41.099689 1
3 update 09.04.2018 18:15:41.099689 1
4 update 09.04.2018 18:15:41.099689 1
But this is 3 update is same values.
How can I restrict this in my trigger?
My trigger function:
CREATE FUNCTION event_fn() AS $BODY$ BEGIN
IF TG_OP = 'INSERT' THEN
INSERT INTO events (event_name, event_date, feature_id) VALUES ('insert', now(), NEW.id);
RETURN NEW;
END IF;
IF TG_OP = 'UPDATE' THEN
INSERT INTO events (event_name, event_date, feature_id) VALUES ('update', now(), NEW.id);
RETURN NEW;
END IF;
IF TG_OP = 'DELETE' THEN
INSERT INTO events (event_name, event_date, feature_id) VALUES ('delete', now(), OLD.id);
RETURN OLD;
END IF;
END;

Answer 1

The best solution would be to opt out of the software that performs several updates instead of actually a single one. However, if you can not do this, you can add a trigger for the events table, e.g.:
create or replace function before_insert_on_events()
returns trigger language plpgsql as $$
begin
if exists (
select 1
from events e
where e.name = new.name
and e.date = new.date
and e.feature_id = new.feature_id)
then new = null;
end if;
return new;
end $$;
create trigger before_insert_on_events
before insert on events
for each row
execute procedure before_insert_on_events();