lemmy/migrations/2023-07-27-134652_remove-expensive-broken-trigger/down.sql
phiresky e315092ee3
remove n^2 part of person triggers, improve community aggregate trigger (#3739)
* remove n^2 part of person triggers, improve community aggregate trigger

* comment out comment_score tests since previously they only accidentally succeeded

* empty
2023-07-27 23:36:51 +02:00

80 lines
No EOL
2.8 KiB
PL/PgSQL

create or replace function person_aggregates_comment_count()
returns trigger language plpgsql
as $$
begin
IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN
update person_aggregates
set comment_count = comment_count + 1 where person_id = NEW.creator_id;
ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN
update person_aggregates
set comment_count = comment_count - 1 where person_id = OLD.creator_id;
-- If the comment gets deleted, the score calculation trigger won't fire,
-- so you need to re-calculate
update person_aggregates ua
set comment_score = cd.score
from (
select u.id,
coalesce(0, sum(cl.score)) as score
-- User join because comments could be empty
from person u
left join comment c on u.id = c.creator_id and c.deleted = 'f' and c.removed = 'f'
left join comment_like cl on c.id = cl.comment_id
group by u.id
) cd
where ua.person_id = OLD.creator_id;
END IF;
return null;
end $$;
create or replace function person_aggregates_post_count()
returns trigger language plpgsql
as $$
begin
IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN
update person_aggregates
set post_count = post_count + 1 where person_id = NEW.creator_id;
ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN
update person_aggregates
set post_count = post_count - 1 where person_id = OLD.creator_id;
-- If the post gets deleted, the score calculation trigger won't fire,
-- so you need to re-calculate
update person_aggregates ua
set post_score = pd.score
from (
select u.id,
coalesce(0, sum(pl.score)) as score
-- User join because posts could be empty
from person u
left join post p on u.id = p.creator_id and p.deleted = 'f' and p.removed = 'f'
left join post_like pl on p.id = pl.post_id
group by u.id
) pd
where ua.person_id = OLD.creator_id;
END IF;
return null;
end $$;
create or replace function community_aggregates_comment_count()
returns trigger language plpgsql
as $$
begin
IF (was_restored_or_created(TG_OP, OLD, NEW)) THEN
update community_aggregates ca
set comments = comments + 1 from comment c, post p
where p.id = c.post_id
and p.id = NEW.post_id
and ca.community_id = p.community_id;
ELSIF (was_removed_or_deleted(TG_OP, OLD, NEW)) THEN
update community_aggregates ca
set comments = comments - 1 from comment c, post p
where p.id = c.post_id
and p.id = OLD.post_id
and ca.community_id = p.community_id;
END IF;
return null;
end $$;