Change post sorting hot rank to use newest comment time. Fixes #517

2 files changed, 194 insertions, 0 deletions

diff --git a/server/migrations/2020-02-08-145624_add_post_newest_activity_time/down.sql b/server/migrations/2020-02-08-145624_add_post_newest_activity_time/down.sql
new file mode 100644
index 00000000..8b912fa3
--- /dev/null
+++ b/server/migrations/2020-02-08-145624_add_post_newest_activity_time/down.sql
@@ -0,0 +1,88 @@
+drop view post_view;
+drop view post_mview;
+drop materialized view post_aggregates_mview;
+drop view post_aggregates_view;
+
+-- regen post view
+create view post_aggregates_view 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;
+
+create materialized view post_aggregates_mview as select * from post_aggregates_view;
+
+create unique index idx_post_aggregates_mview_id on post_aggregates_mview (id);
+
+create view post_view as 
+with all_post as (
+  select
+  pa.*
+  from post_aggregates_view pa
+)
+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
+;
+
+create view post_mview as 
+with all_post as (
+  select
+  pa.*
+  from post_aggregates_mview pa
+)
+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
+;
+
diff --git a/server/migrations/2020-02-08-145624_add_post_newest_activity_time/up.sql b/server/migrations/2020-02-08-145624_add_post_newest_activity_time/up.sql
new file mode 100644
index 00000000..e1541277
--- /dev/null
+++ b/server/migrations/2020-02-08-145624_add_post_newest_activity_time/up.sql
@@ -0,0 +1,106 @@
+-- Adds a newest_activity_time for the post_views, in order to sort by newest comment
+drop view post_view;
+drop view post_mview;
+drop materialized view post_aggregates_mview;
+drop view post_aggregates_view;
+
+-- regen post view
+create view post_aggregates_view 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), 
+  (
+    case when (p.published < ('now'::timestamp - '1 month'::interval)) then p.published -- Prevents necro-bumps
+    else greatest(c.recent_comment_time, p.published)
+    end
+  )
+) as hot_rank,
+(
+  case when (p.published < ('now'::timestamp - '1 month'::interval)) then p.published -- Prevents necro-bumps
+  else greatest(c.recent_comment_time, p.published)
+  end
+) as newest_activity_time 
+from post p
+left join post_like pl on p.id = pl.post_id
+left join (
+  select post_id, 
+  max(published) as recent_comment_time
+  from comment
+  group by 1
+) c on p.id = c.post_id
+group by p.id, c.recent_comment_time;
+
+create materialized view post_aggregates_mview as select * from post_aggregates_view;
+
+create unique index idx_post_aggregates_mview_id on post_aggregates_mview (id);
+
+create view post_view as 
+with all_post as (
+  select
+  pa.*
+  from post_aggregates_view pa
+)
+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
+;
+
+create view post_mview as 
+with all_post as (
+  select
+  pa.*
+  from post_aggregates_mview pa
+)
+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
+;
+