From 0844ba04b518b4cd0a326a2ee0e8431eeb26950d Mon Sep 17 00:00:00 2001 From: Stan Hu Date: Wed, 31 Oct 2018 12:51:11 -0700 Subject: Significantly cut memory usage and SQL queries when reloading diffs By preloading certain models with the diff, we can eliminate many N+1 queries. For a push to the staging GitLab.com www-gitlab-com repository, this eliminates over 3000 SQL queries and appears to bring down the RSS usage by several gigabytes. Relates to https://gitlab.com/gitlab-org/gitlab-ce/issues/49703 --- spec/services/merge_requests/reload_diffs_service_spec.rb | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'spec/services/merge_requests') diff --git a/spec/services/merge_requests/reload_diffs_service_spec.rb b/spec/services/merge_requests/reload_diffs_service_spec.rb index 21f369a3818..546c9f277c5 100644 --- a/spec/services/merge_requests/reload_diffs_service_spec.rb +++ b/spec/services/merge_requests/reload_diffs_service_spec.rb @@ -60,6 +60,17 @@ describe MergeRequests::ReloadDiffsService, :use_clean_rails_memory_store_cachin subject.execute end + + it 'avoids N+1 queries', :request_store do + current_user + merge_request + + control_count = ActiveRecord::QueryRecorder.new do + subject.execute + end.count + + expect { subject.execute }.not_to exceed_query_limit(control_count) + end end end end -- cgit v1.2.1