anchor.diff:  
   type_test() ->
       check_type(bool, "true", true, [true, false]),
  -    check_type(bpchar, "'A'", $A, [1, $1, 255], "c_char"),
  +    check_type(bpchar, "'A'", $A, [1, $1, $Z], "c_char"),
       check_type(int2, "1", 1, [0, 256, -32768, +32767]),
       check_type(int4, "1", 1, [0, 512, -2147483648, +2147483647]),
       check_type(int8, "1", 1, [0, 1024, -9223372036854775808, +9223372036854775807]),
  
positive.code: parameter_get_test() ->
      with_connection(
        fun(C) ->
                {ok, <<"off">>} = pgsql:get_parameter(C, "integer_datetimes")
        end).
  
  parameter_set_test() ->
  
negative.code:                                end,
                                 ok = pgsql:sync(C)
                         end,
                lists:foreach(Insert, [undefined | Values])
        end).
  
  compare(_Type, undefined, undefined) -> true;
  compare(float4, V1, V2)    -> abs(V1 - V2) < 0.000001;
  compare(float8, V1, V2)    -> abs(V1 - V2) < 0.000000000000001;
  compare(_Type, V1, V2)     -> V1 =:= V2.
  
  %% flush mailbox
  