Fix cross database query for RefreshCacheDataService

This commit fixes a cross database query between our 2 new
databases.

ee/app/services/ci/minutes/refresh_cached_data_service.rb

@@ -3,6 +3,8 @@
 module Ci
   module Minutes
     class RefreshCachedDataService
+      BATCH_SIZE = 1_000
+
       def initialize(root_namespace)
         @root_namespace = root_namespace
       end
@@ -28,10 +30,10 @@ module Ci
         return unless ::Feature.enabled?(:ci_pending_builds_maintain_ci_minutes_data, @root_namespace, type: :development, default_enabled: :yaml)
 
         minutes_exceeded = @root_namespace.ci_minutes_quota.minutes_used_up?
-        all_namespaces = @root_namespace.self_and_descendant_ids
+        all_namespace_ids = @root_namespace.self_and_descendant_ids.ids
 
-        ::Gitlab::Database.allow_cross_joins_across_databases(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/345867') do
-          ::Ci::PendingBuild.where(namespace: all_namespaces).update_all(minutes_exceeded: minutes_exceeded)
+        all_namespace_ids.in_groups_of(BATCH_SIZE, minutes_exceeded) do |namespace_ids|
+          ::Ci::PendingBuild.where(namespace: namespace_ids).update_all(minutes_exceeded: minutes_exceeded)
         end
       end
       # rubocop: enable CodeReuse/ActiveRecord

ee/spec/services/ci/minutes/refresh_cached_data_service_spec.rb

@@ -41,6 +41,24 @@ RSpec.describe Ci::Minutes::RefreshCachedDataService do
         expect(pending_build_2.reload.minutes_exceeded).to be_truthy
       end
 
+      context 'when running multiple updates' do
+        before do
+          stub_const("#{described_class}::BATCH_SIZE", 1)
+        end
+
+        it 'runs 2 SQL update queries' do
+          sql_queries = ActiveRecord::QueryRecorder.new { subject }.log
+          update_queries_number = sql_queries.inject(0) do |result, query|
+            result += 1 if query.start_with?("UPDATE")
+            result
+          end
+
+          expect(update_queries_number).to eq(2)
+          expect(pending_build_1.reload.minutes_exceeded).to be_falsey
+          expect(pending_build_2.reload.minutes_exceeded).to be_truthy
+        end
+      end
+
       context 'when ci_pending_builds_maintain_ci_minutes_data is disabled' do
         before do
           stub_feature_flags(ci_pending_builds_maintain_ci_minutes_data: false)