Change 'Scaled' sort to use total interactions instead of monthly users

crates/db_schema/replaceable_schema/utils.sql

@@ -33,16 +33,16 @@ now() - published) < '7 days' THEN
         0.0
     END;
 
-CREATE FUNCTION r.scaled_rank (score numeric, published timestamp with time zone, users_active_month numeric)
+CREATE FUNCTION r.scaled_rank (score numeric, published timestamp with time zone, interactions_month numeric)
     RETURNS double precision
     LANGUAGE sql
     IMMUTABLE PARALLEL SAFE
     -- Add 2 to avoid divide by zero errors
     -- Default for score = 1, active users = 1, and now, is (0.1728 / log(2 + 1)) = 0.3621
-    -- There may need to be a scale factor multiplied to users_active_month, to make
+    -- There may need to be a scale factor multiplied to interactions_month, to make
     -- the log curve less pronounced. This can be tuned in the future.
     RETURN (
-        r.hot_rank (score, published) / log(2 + users_active_month)
+        r.hot_rank (score, published) / log(2 + interactions_month)
 );
 
 -- For tables with `deleted` and `removed` columns, this function determines which rows to include in a count.

crates/db_schema/src/utils.rs

@@ -531,7 +531,7 @@ pub mod functions {
 
   define_sql_function! {
     #[sql_name = "r.scaled_rank"]
-    fn scaled_rank(score: BigInt, time: Timestamptz, users_active_month: BigInt) -> Double;
+    fn scaled_rank(score: BigInt, time: Timestamptz, interactions_month: BigInt) -> Double;
   }
 
   define_sql_function! {

src/scheduled_tasks.rs

@@ -233,14 +233,22 @@ async fn process_post_aggregates_ranks_in_batches(conn: &mut AsyncPgConnection)
            AND (pa.hot_rank != 0 OR pa.hot_rank_active != 0)
            ORDER BY pa.published
            LIMIT $2
-               FOR UPDATE SKIP LOCKED)
+          FOR UPDATE SKIP LOCKED),
+      community_interactions AS (
+          SELECT community_id,
+                 SUM(comments + upvotes + downvotes) as total_interactions
+          FROM post_aggregates
+          WHERE published >= date_trunc('month', CURRENT_TIMESTAMP - interval '1 month')
+          GROUP BY community_id)
       UPDATE post_aggregates pa
       SET hot_rank = r.hot_rank(pa.score, pa.published),
           hot_rank_active = r.hot_rank(pa.score, pa.newest_comment_time_necro),
-           scaled_rank = r.scaled_rank(pa.score, pa.published, ca.users_active_month)
-         FROM batch, community_aggregates ca
-         WHERE pa.post_id = batch.post_id and pa.community_id = ca.community_id RETURNING pa.published;
-    "#,
+          scaled_rank = r.scaled_rank(pa.score, pa.published, ci.total_interactions)
+      FROM batch, community_interactions ci
+      WHERE pa.post_id = batch.post_id
+      AND pa.community_id = ci.community_id
+      RETURNING pa.published;
+"#,
     )
     .bind::<Timestamptz, _>(previous_batch_last_published)
     .bind::<Integer, _>(update_batch_size)