Fix N+1 query, after we removed second_level_cache.

app/controllers/admin/users_controller.rb

@@ -1,7 +1,7 @@
 module Admin
   class UsersController < Admin::ApplicationController
     def index
-      scope = User.all
+      scope = User.all.includes(:profile)
       scope = scope.where(type: params[:type]) if params[:type].present?
       scope = scope.where(state: params[:state]) if params[:state].present?
       field = params[:field] || "login"

app/controllers/topics/list_actions.rb

@@ -62,7 +62,7 @@ def topics_scope(base_scope = Topic, without_nodes: true)
       end
 
       # must include :user, because it's uses for _topic.html.erb fragment cache_key
-      scope.includes(:user)
+      scope.includes(:user, :node, :last_reply_user)
     end
   end
 end

app/controllers/topics_controller.rb

@@ -10,9 +10,9 @@ class TopicsController < ApplicationController
   def index
     @suggest_topics = []
     if params[:page].to_i <= 1
-      @suggest_topics = topics_scope.suggest.includes(:node).limit(3)
+      @suggest_topics = topics_scope.suggest.limit(3)
     end
-    @topics = topics_scope.without_suggest.last_actived.includes(:node).page(params[:page])
+    @topics = topics_scope.without_suggest.last_actived.page(params[:page])
     @page_title = t("menu.topics")
     @read_topic_ids = []
     if current_user
@@ -21,7 +21,7 @@ def index
   end
 
   def feed
-    @topics = Topic.recent.without_ban.without_hide_nodes.includes(:node, :user, :last_reply_user).limit(20)
+    @topics = Topic.recent.without_ban.without_hide_nodes.limit(20)
     render layout: false if stale?(@topics)
   end
 
@@ -35,19 +35,19 @@ def node
 
   def node_feed
     @node = Node.find(params[:id])
-    @topics = @node.topics.recent.limit(20)
+    @topics = @node.topics.includes(:user, :node, :last_reply_user).recent.limit(20)
     render layout: false
   end
 
   def show
-    @topic = Topic.unscoped.includes(:user).find(params[:id])
+    @topic = Topic.unscoped.includes(:user, :last_reply_user).find(params[:id])
     render_404 if @topic.deleted?
 
     @node = @topic.node
     @show_raw = params[:raw] == "1"
     @can_reply = can?(:create, Reply)
 
-    @replies = Reply.unscoped.where(topic_id: @topic.id).order(:id).all
+    @replies = Reply.unscoped.where(topic_id: @topic.id).includes(:user).order(:id).all
     @user_like_reply_ids = current_user&.like_reply_ids_by_replies(@replies) || []
 
     @has_followed = current_user&.follow_topic?(@topic)

app/controllers/users/user_actions.rb

@@ -74,7 +74,7 @@ def only_user!
 
     def user_show
       @replies = @user.replies.without_system.fields_for_list.recent.includes(:topic).limit(10)
-      @topics = @user.topics.fields_for_list.high_likes.page(params[:page])
+      @topics = @user.topics.fields_for_list.high_likes.includes(:node).page(params[:page])
     end
   end
 end

app/controllers/users_controller.rb

@@ -23,7 +23,7 @@ def index
   end
 
   def feed
-    @topics = @user.topics.recent.limit(20)
+    @topics = @user.topics.includes(:node).recent.limit(20)
   end
 
   def city