Cache table_exists?('application_settings') to reduce repeated schema reloads

Closes #43355

1 files changed, 12 insertions, 0 deletions

diff --git a/spec/lib/gitlab/database_spec.rb b/spec/lib/gitlab/database_spec.rb
index 689bbbfaa8d..1fe1d3926ad 100644
--- a/spec/lib/gitlab/database_spec.rb
+++ b/spec/lib/gitlab/database_spec.rb
@@ -298,6 +298,18 @@ describe Gitlab::Database do
     end
   end
 
+  describe '.cached_table_exists?' do
+    it 'only retrieves data once per table' do
+      expect(ActiveRecord::Base.connection).to receive(:table_exists?).with(:projects).once.and_call_original
+      expect(ActiveRecord::Base.connection).to receive(:table_exists?).with(:bogus_table_name).once.and_call_original
+
+      2.times do
+        expect(described_class.cached_table_exists?(:projects)).to be_truthy
+        expect(described_class.cached_table_exists?(:bogus_table_name)).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)