From: alpaca-tc <alpaca-tc@alpaca.tc>
Date: Wed, 10 May 2017 18:33:32 +0000 (+0900)
Subject: Add `account_id DESC` to optimize PrecomputeFeedService (#2967)
X-Git-Url: https://git.xn--scling-oua.cat.family/?a=commitdiff_plain;h=c3ef5d5414ac1fee5471d7063616a4b72a408e11;p=mastodon.git

Add `account_id DESC` to optimize PrecomputeFeedService (#2967)
---

diff --git a/app/services/precompute_feed_service.rb b/app/services/precompute_feed_service.rb
index 07dcb81da..46f0057cb 100644
--- a/app/services/precompute_feed_service.rb
+++ b/app/services/precompute_feed_service.rb
@@ -6,7 +6,8 @@ class PrecomputeFeedService < BaseService
   # @param [Account] account
   def call(_, account)
     redis.pipelined do
-      Status.as_home_timeline(account).limit(FeedManager::MAX_ITEMS / 4).each do |status|
+      # NOTE: Added `id desc, account_id desc` to `ORDER BY` section to optimize query.
+      Status.as_home_timeline(account).order(account_id: :desc).limit(FeedManager::MAX_ITEMS / 4).each do |status|
         next if status.direct_visibility? || FeedManager.instance.filter?(:home, status, account.id)
         redis.zadd(FeedManager.instance.key(:home, account.id), status.id, status.reblog? ? status.reblog_of_id : status.id)
       end