migrations/2021-01-05-200932_add_hot_rank_indexes/up.sql

   1 -- Need to add immutable to the hot_rank function in order to index by it
   2 -- Rank = ScaleFactor * sign(Score) * log(1 + abs(Score)) / (Time + 2)^Gravity
   3 CREATE OR REPLACE FUNCTION hot_rank (score numeric, published timestamp without time zone)
   4     RETURNS integer
   5     AS $$
   6 BEGIN
   7     -- hours_diff:=EXTRACT(EPOCH FROM (timezone('utc',now()) - published))/3600
   8     RETURN floor(10000 * log(greatest (1, score + 3)) / power(((EXTRACT(EPOCH FROM (timezone('utc', now()) - published)) / 3600) + 2), 1.8))::integer;
   9 END;
  10 $$
  11 LANGUAGE plpgsql
  12 IMMUTABLE;
  13
  14 -- Post_aggregates
  15 CREATE INDEX idx_post_aggregates_stickied_hot ON post_aggregates (stickied DESC, hot_rank (score, published) DESC, published DESC);
  16
  17 CREATE INDEX idx_post_aggregates_hot ON post_aggregates (hot_rank (score, published) DESC, published DESC);
  18
  19 CREATE INDEX idx_post_aggregates_stickied_active ON post_aggregates (stickied DESC, hot_rank (score, newest_comment_time) DESC, newest_comment_time DESC);
  20
  21 CREATE INDEX idx_post_aggregates_active ON post_aggregates (hot_rank (score, newest_comment_time) DESC, newest_comment_time DESC);
  22
  23 CREATE INDEX idx_post_aggregates_stickied_score ON post_aggregates (stickied DESC, score DESC);
  24
  25 CREATE INDEX idx_post_aggregates_score ON post_aggregates (score DESC);
  26
  27 CREATE INDEX idx_post_aggregates_stickied_published ON post_aggregates (stickied DESC, published DESC);
  28
  29 CREATE INDEX idx_post_aggregates_published ON post_aggregates (published DESC);
  30
  31 -- Comment
  32 CREATE INDEX idx_comment_published ON comment (published DESC);
  33
  34 -- Comment_aggregates
  35 CREATE INDEX idx_comment_aggregates_hot ON comment_aggregates (hot_rank (score, published) DESC, published DESC);
  36
  37 CREATE INDEX idx_comment_aggregates_score ON comment_aggregates (score DESC);
  38
  39 -- User
  40 CREATE INDEX idx_user_published ON user_ (published DESC);
  41
  42 -- User_aggregates
  43 CREATE INDEX idx_user_aggregates_comment_score ON user_aggregates (comment_score DESC);
  44
  45 -- Community
  46 CREATE INDEX idx_community_published ON community (published DESC);
  47
  48 -- Community_aggregates
  49 CREATE INDEX idx_community_aggregates_hot ON community_aggregates (hot_rank (subscribers, published) DESC, published DESC);
  50
  51 CREATE INDEX idx_community_aggregates_subscribers ON community_aggregates (subscribers DESC);
  52