Optimized multiple DB queries

CHANGELOG.md

@@ -11,6 +11,7 @@
 - Update events heading style
 - Update some icons
 - Optimized the load time of the payment schedules list
+- Optimized multiple DB queries
 - Fix a bug: do not load Stripe if no keys were defined
 - Fix a bug: some links redirect to the home page instead of triggering the requested action
 - Fix a bug: exports to Excel are corrupted (#49)

Gemfile

@@ -29,6 +29,7 @@ group :development do
   # Access an IRB console on exception pages or by using <%= console %> in views
   gem 'active_record_query_trace'
   gem 'awesome_print'
+  gem 'bullet'
   gem 'coveralls_reborn', '~> 0.18.0', require: false
   gem 'foreman'
   gem 'web-console', '>= 3.3.0'

Gemfile.lock

@@ -67,6 +67,9 @@ GEM
     bootsnap (1.4.6)
       msgpack (~> 1.0)
     builder (3.2.4)
+    bullet (7.0.0)
+      activesupport (>= 3.0.0)
+      uniform_notifier (~> 1.11)
     camertron-eprun (1.1.1)
     carrierwave (2.1.1)
       activemodel (>= 5.0.0)
@@ -394,6 +397,7 @@ GEM
     tzinfo-data (1.2020.4)
       tzinfo (>= 1.0.0)
     unicode-display_width (1.4.1)
+    uniform_notifier (1.14.2)
     vcr (6.0.0)
     virtus (1.0.5)
       axiom-types (~> 0.1)
@@ -431,6 +435,7 @@ DEPENDENCIES
   apipie-rails
   awesome_print
   bootsnap
+  bullet
   carrierwave
   caxlsx
   caxlsx_rails
@@ -498,4 +503,4 @@ DEPENDENCIES
   webpacker (~> 5.x)
 
 BUNDLED WITH
-   2.1.4
+   2.2.19

app/controllers/api/notifications_controller.rb

@@ -6,12 +6,15 @@ class API::NotificationsController < API::ApiController
   include NotifyWith::NotificationsApi
   before_action :authenticate_user!
 
+  # notifications can have anything attached, so we won't eager load the whole database
+  around_action :skip_bullet, if: -> { defined?(Bullet) }
+
   # Number of notifications added to the page when the user clicks on 'load next notifications'
   NOTIFICATIONS_PER_PAGE = 15
 
   def index
     loop do
-      @notifications = current_user.notifications.page(params[:page]).per(NOTIFICATIONS_PER_PAGE).order('created_at DESC')
+      @notifications = current_user.notifications.includes(:attached_object).page(params[:page]).per(NOTIFICATIONS_PER_PAGE).order('created_at DESC')
       # we delete obsolete notifications on first access
       break unless delete_obsoletes(@notifications)
     end
@@ -24,7 +27,7 @@ class API::NotificationsController < API::ApiController
 
   def last_unread
     loop do
-      @notifications = current_user.notifications.where(is_read: false).limit(3).order('created_at DESC')
+      @notifications = current_user.notifications.includes(:attached_object).where(is_read: false).limit(3).order('created_at DESC')
       # we delete obsolete notifications on first access
       break unless delete_obsoletes(@notifications)
     end

app/controllers/application_controller.rb

@@ -80,4 +80,13 @@ class ApplicationController < ActionController::Base
   def authenticate_user!
     super
   end
+
+  # N+1 query detection (https://github.com/flyerhzm/bullet)
+  def skip_bullet
+    previous_value = Bullet.enable?
+    Bullet.enable = false
+    yield
+  ensure
+    Bullet.enable = previous_value
+  end
 end

app/models/payment_schedule.rb

@@ -50,7 +50,7 @@ class PaymentSchedule < PaymentDocument
   end
 
   def gateway_subscription
-    payment_gateway_objects.map(&:gateway_object).find(&:subscription?)
+    payment_gateway_objects.includes(:payment_gateway_object).map(&:gateway_object).find(&:subscription?)
   end
 
   def gateway_order

app/services/invoices_service.rb

@@ -9,7 +9,7 @@ class InvoicesService
   # @param size {number} number of items per page
   # @param filters {Hash} allowed filters: number, customer, date.
   def self.list(order_key, direction, page, size, filters = {})
-    invoices = Invoice.includes(:avoir, :invoicing_profile, invoice_items: %i[subscription invoice_item])
+    invoices = Invoice.includes(:avoir, :operator_profile, :payment_gateway_object, invoicing_profile: [:user])
                       .joins(:invoicing_profile)
                       .order("#{order_key} #{direction}")
                       .page(page)

app/services/payment_schedule_service.rb

@@ -127,7 +127,7 @@ class PaymentScheduleService
   # @param filters {Hash} allowed filters: reference, customer, date.
   ##
   def self.list(page, size, filters = {})
-    ps = PaymentSchedule.includes(:invoicing_profile, :payment_schedule_items, :payment_schedule_objects)
+    ps = PaymentSchedule.includes(:operator_profile, :payment_schedule_items, invoicing_profile: [:user])
                         .joins(:invoicing_profile)
                         .order('payment_schedules.created_at DESC')
                         .page(page)

config/environments/development.rb

@@ -1,6 +1,17 @@
 # frozen_string_literal: true
 
 Rails.application.configure do
+  # https://github.com/flyerhzm/bullet
+  # In development, Bullet will find and report N+1 DB requests
+  config.after_initialize do
+    Bullet.enable        = true
+    Bullet.alert         = true
+    Bullet.bullet_logger = true
+    Bullet.console       = true
+    Bullet.rails_logger  = true
+    Bullet.add_footer    = true
+  end
+
   # Settings specified here will take precedence over those in config/application.rb.
 
   # In the development environment your application's code is reloaded on