Update project overrides query

app/models/concerns/integration.rb

@@ -6,12 +6,12 @@ module Integration
   class_methods do
     def with_custom_integration_for(integration, page = nil, per = nil)
       custom_integration_project_ids = Service
+        .select(:project_id)
         .where(type: integration.type)
         .where(inherit_from_id: nil)
-        .distinct # Required until https://gitlab.com/gitlab-org/gitlab/-/issues/207385
+        .where.not(project_id: nil)
         .page(page)
         .per(per)
-        .pluck(:project_id)
 
       Project.where(id: custom_integration_project_ids)
     end

changelogs/unreleased/218252-update-project-overrides-query.yml

+---
+title: Add index services on project and type where inherit is null
+merge_request: 59168
+author:
+type: other

db/migrate/20210414095944_add_index_services_on_project_and_type_where_inherit_null.rb

+# frozen_string_literal: true
+
+class AddIndexServicesOnProjectAndTypeWhereInheritNull < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  INDEX_NAME = 'index_services_on_project_and_type_where_inherit_null'
+
+  def up
+    add_concurrent_index(:services, [:project_id, :type], where: 'inherit_from_id IS NULL', name: INDEX_NAME)
+  end
+
+  def down
+    remove_concurrent_index_by_name(:services, INDEX_NAME)
+  end
+end

db/schema_migrations/20210414095944

+843d9eabf8b67fe10d9eb453e887032d5b88b8594ae666bc6c6ac81e20e1ab53
\ No newline at end of file

db/structure.sql

@@ -23864,6 +23864,8 @@ CREATE INDEX index_service_desk_enabled_projects_on_id_creator_id_created_at ON
 
 CREATE INDEX index_services_on_inherit_from_id ON services USING btree (inherit_from_id);
 
+CREATE INDEX index_services_on_project_and_type_where_inherit_null ON services USING btree (project_id, type) WHERE (inherit_from_id IS NULL);
+
 CREATE UNIQUE INDEX index_services_on_project_id_and_type_unique ON services USING btree (project_id, type);
 
 CREATE INDEX index_services_on_template ON services USING btree (template);

spec/models/integration_spec.rb

@@ -6,23 +6,28 @@ RSpec.describe Integration do
   let_it_be(:project_1) { create(:project) }
   let_it_be(:project_2) { create(:project) }
   let_it_be(:project_3) { create(:project) }
+  let_it_be(:project_4) { create(:project) }
   let_it_be(:instance_integration) { create(:jira_service, :instance) }
 
   before do
     create(:jira_service, project: project_1, inherit_from_id: instance_integration.id)
     create(:jira_service, project: project_2, inherit_from_id: nil)
-    create(:slack_service, project: project_3, inherit_from_id: nil)
+    create(:jira_service, group: create(:group), project: nil, inherit_from_id: nil)
+    create(:jira_service, project: project_3, inherit_from_id: nil)
+    create(:slack_service, project: project_4, inherit_from_id: nil)
   end
 
   describe '.with_custom_integration_for' do
     it 'returns projects with custom integrations' do
-      expect(Project.with_custom_integration_for(instance_integration)).to contain_exactly(project_2)
+      # We use pagination to verify that the group is excluded from the query
+      expect(Project.with_custom_integration_for(instance_integration, 0, 2)).to contain_exactly(project_2, project_3)
+      expect(Project.with_custom_integration_for(instance_integration)).to contain_exactly(project_2, project_3)
     end
   end
 
   describe '.without_integration' do
     it 'returns projects without integration' do
-      expect(Project.without_integration(instance_integration)).to contain_exactly(project_3)
+      expect(Project.without_integration(instance_integration)).to contain_exactly(project_4)
     end
   end
 end