primary_keys

# File activerecord/lib/active_record/connection_adapters/schema_cache.rb, line 298
      def primary_keys(pool, table_name)
        @primary_keys.fetch(table_name) do
          pool.with_connection do |connection|
            if data_source_exists?(pool, table_name)
              @primary_keys[deep_deduplicate(table_name)] = deep_deduplicate(connection.primary_key(table_name))
            end
          end
        end
      end