Speed-up adding new models to has-many association scope

README.md

@@ -59,11 +59,9 @@ end
 
 #### Performance
 
-In general you are safe to use JSONB HABTM for models that won't have many associations on both sides.
+Compared to regular associations, fetching models associated via JSONB column has no drops in performance.
 
-If you plan to have associations where one side has many records on the other side (more then ~500), adding new records to existing associations scope will be slower then with traditional approach.
-
-Below you can see benchmark results for adding new associations to the association scope:
+Adding new connections is slightly faster with JSONB, for scopes up to 500 records connected to another record (total count of records in the table does not matter that much. If you have more then ~500 records connected to one record on average, and you want to add new records to the scope, JSONB associations will be slower then traditional:
 
 <img src="https://github.com/lebedev-yury/activerecord-jsonb-associations/blob/master/doc/images/adding-associations.png?raw=true | width=500" alt="JSONB HAMTB is slower on adding associations" width="600">
 

benchmarks/habtm.rake

@@ -7,7 +7,9 @@ require 'benchmark/ips'
 namespace :benchmarks do
   desc 'Regular vs JSONB HABTM benchmarks'
   task :habtm do
-    (10..5_010).step(500).to_a.each do |associations_count|
+    [
+      10, 100, 500, 1000, 2_500, 5_000, 10_000
+    ].to_a.each do |associations_count|
       user = User.create
       user_with_groups_only = User.create
       user_with_labels_only = User.create
@@ -20,6 +22,54 @@ namespace :benchmarks do
                              associations_count,
                              users: [user, user_with_labels_only]
 
+      Benchmark.ips do |x|
+        x.config(warmup: 0)
+
+        x.report(
+          "Regular: fetching associations with #{associations_count} existing"
+        ) do
+          ActiveRecord::Base.transaction do
+            Group.uncached { user.groups.reload }
+            raise ActiveRecord::Rollback
+          end
+        end
+
+        x.report(
+          "JSONB: fetching associations with #{associations_count} existing"
+        ) do
+          ActiveRecord::Base.transaction do
+            Label.uncached { user.labels.reload }
+            raise ActiveRecord::Rollback
+          end
+        end
+
+        x.compare!
+      end
+
+      Benchmark.ips do |x|
+        x.config(warmup: 0)
+
+        x.report(
+          "Regular: getting association ids with #{associations_count} existing"
+        ) do
+          ActiveRecord::Base.transaction do
+            Group.uncached { user.group_ids }
+            raise ActiveRecord::Rollback
+          end
+        end
+
+        x.report(
+          "JSONB: getting association ids with #{associations_count} existing"
+        ) do
+          ActiveRecord::Base.transaction do
+            Label.uncached { user.label_ids }
+            raise ActiveRecord::Rollback
+          end
+        end
+
+        x.compare!
+      end
+
       Benchmark.ips do |x|
         x.config(warmup: 0)
 

lib/activerecord/jsonb/associations/has_many_association.rb

@@ -58,19 +58,25 @@ def create_scope
         end
         # rubocop:enable Metrics/AbcSize
 
-        # rubocop:disable Metrics/AbcSize
+        # rubocop:disable Metrics/MethodLength, Metrics/AbcSize
         def insert_record(record, validate = true, raise = false)
-          super.tap do
+          super.tap do |super_result|
             next unless options.key?(:store)
+            next unless super_result
 
             key = "#{record.model_name.singular}_ids"
-            store = owner[options[:store]] || {}
-            store[key] ||= []
-            store[key] << record.id
-            owner.update_column(options[:store], store)
+            jsonb_column = options[:store]
+
+            owner.class.where(
+              owner.class.primary_key => owner[owner.class.primary_key]
+            ).update_all(%(
+              #{jsonb_column} = jsonb_set(#{jsonb_column}, '{#{key}}',
+              coalesce(#{jsonb_column}->'#{key}', '[]'::jsonb) ||
+              '[#{record[klass.primary_key]}]'::jsonb)
+            ))
           end
         end
-        # rubocop:enable Metrics/AbcSize
+        # rubocop:enable Metrics/MethodLength, Metrics/AbcSize
 
         def delete_records(records, method)
           return super unless options.key?(:store)