Cache column_exists? for application settings

This is most a backport of
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4987/diffs but includes
other columns that use column_exists? in a way that may cause unnecessary
schema loads.

1 files changed, 11 insertions, 0 deletions

diff --git a/spec/lib/gitlab/database_spec.rb b/spec/lib/gitlab/database_spec.rb
index b2f13fae73f..689bbbfaa8d 100644
--- a/spec/lib/gitlab/database_spec.rb
+++ b/spec/lib/gitlab/database_spec.rb
@@ -287,6 +287,17 @@ describe Gitlab::Database do
     end
   end
 
+  describe '.cached_column_exists?' do
+    it 'only retrieves data once' do
+      expect(ActiveRecord::Base.connection).to receive(:columns).once.and_call_original
+
+      2.times do
+        expect(described_class.cached_column_exists?(:projects, :id)).to be_truthy
+        expect(described_class.cached_column_exists?(:projects, :bogus_column)).to be_falsey
+      end
+    end
+  end
+
   describe '#true_value' do
     it 'returns correct value for PostgreSQL' do
       expect(described_class).to receive(:postgresql?).and_return(true)