Back to just indexes.

server/migrations/2020-01-11-012452_add_indexes/down.sql

@@ -1,5 +1,3 @@
--- This file should undo anything in `up.sql`
-
 drop index idx_post_creator;
 drop index idx_post_community;
 
@@ -16,58 +14,3 @@ drop index idx_comment_like_post;
 
 drop index idx_community_creator;
 drop index idx_community_category;
-
-drop index idx_community_follower_community;
-drop index idx_community_follower_user;
-
-drop index idx_community_user_ban_community;
-drop index idx_community_user_ban_user;
-
-drop view post_view;
-create view post_view as
-with all_post as
-(
-  select        
-  p.*,
-  (select u.banned from user_ u where p.creator_id = u.id) as banned,
-  (select cb.id::bool from community_user_ban cb where p.creator_id = cb.user_id and p.community_id = cb.community_id) as banned_from_community,
-  (select name from user_ where p.creator_id = user_.id) as creator_name,
-  (select avatar from user_ where p.creator_id = user_.id) as creator_avatar,
-  (select name from community where p.community_id = community.id) as community_name,
-  (select removed from community c where p.community_id = c.id) as community_removed,
-  (select deleted from community c where p.community_id = c.id) as community_deleted,
-  (select nsfw from community c where p.community_id = c.id) as community_nsfw,
-  (select count(*) from comment where comment.post_id = p.id) as number_of_comments,
-  coalesce(sum(pl.score), 0) as score,
-  count (case when pl.score = 1 then 1 else null end) as upvotes,
-  count (case when pl.score = -1 then 1 else null end) as downvotes,
-  hot_rank(coalesce(sum(pl.score) , 0), p.published) as hot_rank
-  from post p
-  left join post_like pl on p.id = pl.post_id
-  group by p.id
-)
-
-select
-ap.*,
-u.id as user_id,
-coalesce(pl.score, 0) as my_vote,
-(select cf.id::bool from community_follower cf where u.id = cf.user_id and cf.community_id = ap.community_id) as subscribed,
-(select pr.id::bool from post_read pr where u.id = pr.user_id and pr.post_id = ap.id) as read,
-(select ps.id::bool from post_saved ps where u.id = ps.user_id and ps.post_id = ap.id) as saved
-from user_ u
-cross join all_post ap
-left join post_like pl on u.id = pl.user_id and ap.id = pl.post_id
-
-union all
-
-select 
-ap.*,
-null as user_id,
-null as my_vote,
-null as subscribed,
-null as read,
-null as saved
-from all_post ap
-;
-
-

server/migrations/2020-01-11-012452_add_indexes/up.sql

@@ -1,5 +1,4 @@
 -- Go through all the tables joins, optimize every view, CTE, etc.
-
 create index idx_post_creator on post (creator_id);
 create index idx_post_community on post (community_id);
 
@@ -16,60 +15,3 @@ create index idx_comment_like_post on comment_like (post_id);
 
 create index idx_community_creator on community (creator_id);
 create index idx_community_category on community (category_id);
-
-create index idx_community_follower_community on community_follower (community_id);
-create index idx_community_follower_user on community_follower (user_id);
-
-create index idx_community_user_ban_community on community_user_ban (community_id);
-create index idx_community_user_ban_user on community_user_ban (user_id);
-
--- optimize post_view
-
-drop view post_view;
-create view post_view as
-with all_post as
-(
-  select        
-  p.*,
-  u.banned as banned,
-  (select cb.id::bool from community_user_ban cb where p.creator_id = cb.user_id and p.community_id = cb.community_id) as banned_from_community,
-  u.name as creator_name, 
-  u.avatar as creator_avatar,
-  c.name as community_name, 
-  c.removed as community_removed,
-  c.deleted as community_deleted,
-  c.nsfw as community_nsfw,
-  (select count(*) from comment where comment.post_id = p.id) as number_of_comments,
-  coalesce(sum(pl.score), 0) as score,
-  count (case when pl.score = 1 then 1 else null end) as upvotes,
-  count (case when pl.score = -1 then 1 else null end) as downvotes,
-  hot_rank(coalesce(sum(pl.score) , 0), p.published) as hot_rank
-  from post p
-  left join post_like pl on p.id = pl.post_id
-  inner join user_ u on p.creator_id = u.id
-  inner join community c on p.community_id = c.id
-  group by p.id, u.banned, u.name, u.avatar, c.name, c.removed, c.deleted, c.nsfw
-)
-
-select
-ap.*,
-u.id as user_id,
-coalesce(pl.score, 0) as my_vote,
-(select cf.id::bool from community_follower cf where u.id = cf.user_id and cf.community_id = ap.community_id) as subscribed,
-(select pr.id::bool from post_read pr where u.id = pr.user_id and pr.post_id = ap.id) as read,
-(select ps.id::bool from post_saved ps where u.id = ps.user_id and ps.post_id = ap.id) as saved
-from user_ u
-cross join all_post ap
-left join post_like pl on u.id = pl.user_id and ap.id = pl.post_id
-
-union all
-
-select 
-ap.*,
-null as user_id,
-null as my_vote,
-null as subscribed,
-null as read,
-null as saved
-from all_post ap
-;

server/query_testing/generate_explain_reports.sh

@@ -14,6 +14,9 @@ psql -qAt -U lemmy -f explain.sql > comment_view.json
 echo "explain (analyze, format json) select * from community_view where user_id is null order by hot_rank desc" > explain.sql
 psql -qAt -U lemmy -f explain.sql > community_view.json
 
+echo "explain (analyze, format json) select * from site_view limit 1" > explain.sql
+psql -qAt -U lemmy -f explain.sql > site_view.json
+
 grep "Execution Time" *.json
 
 rm explain.sql