1 files changed, 27 insertions, 0 deletions
diff --git a/lib/gitlab/database/migrations/observers/query_log.rb b/lib/gitlab/database/migrations/observers/query_log.rb
new file mode 100644
index 00000000000..45df07fe391
--- /dev/null
+++ b/lib/gitlab/database/migrations/observers/query_log.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module Migrations
+      module Observers
+        class QueryLog < MigrationObserver
+          def before
+            @logger_was = ActiveRecord::Base.logger
+            @log_file_path = File.join(Instrumentation::RESULT_DIR, 'current.log')
+            @logger = Logger.new(@log_file_path)
+            ActiveRecord::Base.logger = @logger
+          end
+
+          def after
+            ActiveRecord::Base.logger = @logger_was
+            @logger.close
+          end
+
+          def record(observation)
+            File.rename(@log_file_path, File.join(Instrumentation::RESULT_DIR, "#{observation.migration}.log"))
+          end
+        end
+      end
+    end
+  end
+end