improve perf of rank view perf

api/resolvers/item.js

@@ -361,10 +361,10 @@ export default {
                     FROM "Item"
                     ${await joinSatRankView(me, models)}
                     ${subClause(sub, 2, 'Item', true)}
-                    ORDER BY rank DESC NULLS LAST, id DESC
+                    ORDER BY rank ASC
                     OFFSET $1
                     LIMIT ${LIMIT}`,
-                orderBy: 'ORDER BY rank DESC NULLS LAST, id DESC'
+                orderBy: 'ORDER BY rank ASC'
               }, decodedCursor.offset, ...subArr)
 
               if (decodedCursor.offset === 0) {

prisma/migrations/20230524062059_rank_again/migration.sql

@@ -0,0 +1,58 @@
+-- our last attempt was slow because nearly every row had to change given
+-- that we store the score and all other columns rather than the rank ...
+-- the score always changes and other columns are denormalized (and also change) ..
+-- if instead we just store the rank, concurrent refreshes should be faster
+-- as they'll be near identical
+-- we also limit the view to 2100 rows which is more than any reasonable person would view
+DROP MATERIALIZED VIEW IF EXISTS sat_rank_wwm_view;
+CREATE MATERIALIZED VIEW IF NOT EXISTS sat_rank_wwm_view AS
+SELECT id, row_number() OVER (ORDER BY
+    ((GREATEST("weightedVotes", POWER("weightedVotes", 1.2)) + "weightedComments"/2)
+    /
+    POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - created_at))/3600), 1.3)
+    +
+    (boost/5000::float)
+    /
+    POWER(EXTRACT(EPOCH FROM (now_utc() - created_at))/3600+2, 2.6)) DESC NULLS LAST, id DESC) as rank
+FROM "Item"
+WHERE "parentId" IS NULL AND NOT bio AND "pinId" IS NULL AND "deletedAt" IS NULL
+AND "weightedVotes" > 0
+ORDER BY
+    ((GREATEST("weightedVotes", POWER("weightedVotes", 1.2)) + "weightedComments"/2)
+    /
+    POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - created_at))/3600), 1.3)
+    +
+    (boost/5000::float)
+    /
+    POWER(EXTRACT(EPOCH FROM (now_utc() - created_at))/3600+2, 2.6)) DESC NULLS LAST, id DESC
+LIMIT 2100;
+
+CREATE UNIQUE INDEX IF NOT EXISTS sat_rank_wwm_view_idx ON sat_rank_wwm_view(rank ASC);
+
+-- we do the same for the tender view
+DROP MATERIALIZED VIEW IF EXISTS sat_rank_tender_view;
+CREATE MATERIALIZED VIEW IF NOT EXISTS sat_rank_tender_view AS
+SELECT id, row_number() OVER (ORDER BY
+    ((GREATEST(ABS("weightedVotes" - "weightedDownVotes"), POWER(ABS("weightedVotes" - "weightedDownVotes"), 1.2))
+        + "weightedComments"/2)
+    /
+    POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - created_at))/3600), 1.3)
+    +
+    (boost/5000::float)
+    /
+    POWER(EXTRACT(EPOCH FROM (now_utc() - created_at))/3600+2, 2.6)) DESC NULLS LAST, id DESC) AS rank
+FROM "Item"
+WHERE "parentId" IS NULL AND NOT bio AND "pinId" IS NULL AND "deletedAt" IS NULL
+AND "weightedVotes" > "weightedDownVotes"
+ORDER BY
+    ((GREATEST(ABS("weightedVotes" - "weightedDownVotes"), POWER(ABS("weightedVotes" - "weightedDownVotes"), 1.2))
+        + "weightedComments"/2)
+    /
+    POWER(GREATEST(3, EXTRACT(EPOCH FROM (now_utc() - created_at))/3600), 1.3)
+    +
+    (boost/5000::float)
+    /
+    POWER(EXTRACT(EPOCH FROM (now_utc() - created_at))/3600+2, 2.6)) DESC NULLS LAST, id DESC
+LIMIT 2100;
+
+CREATE UNIQUE INDEX IF NOT EXISTS sat_rank_tender_view_idx ON sat_rank_tender_view(rank ASC);