# File lib/rubyrep/proxy_connection.rb, line 150
    def primary_key_names(table_name, options = {})
      return connection.primary_key_names(table_name) if options[:raw]
      
      self.primary_key_names_cache ||= {}
      result = primary_key_names_cache[table_name]
      unless result
        result = manual_primary_keys[table_name] || connection.primary_key_names(table_name)
        primary_key_names_cache[table_name] = result
      end
      result
    end