fetch

# File activerecord/lib/active_record/connection_adapters/postgresql/oid.rb, line 276
          def fetch(ftype, fmod)
            # The type for the numeric depends on the width of the field,
            # so we'll do something special here.
            #
            # When dealing with decimal columns:
            #
            # places after decimal  = fmod - 4 & 0xffff
            # places before decimal = (fmod - 4) >> 16 & 0xffff
            if ftype == 1700 && (fmod - 4 & 0xffff).zero?
              ftype = 23
            end

            @mapping.fetch(ftype) { |oid| yield oid, fmod }
          end