Re: what is good solution for support NULL inside string_to_array function?

2010/5/4 Tom Lane <tgl@sss.pgh.pa.us>:
> Josh Berkus <josh@agliodbs.com> writes:
>>> quietly removing NULL is maybe good for compatibility but is wrong for
>>> functionality.
>
>> I agree.  I wasn't aware of this little misfeature.
>
>> Default display for NULL should be a zero-length string.
>
> That's just as broken as Pavel's suggestion.  Unless you have something
> that is guaranteed distingishable from the output of any non-null value,
> you really can't make a significant improvement here.
>

I wouldn't modify current two params string_to_array and
array_to_string function. So there are not any default string (maybe
empty string) for NULL. My proposal is new three params functions with
>>>explicit<<< "null string" definition. This cannot break
compatibility and enhance functionality - It is just short cut for
code from my proposal - in C this functionality can by implemented
much faster.

Regards
Pavel

>                        regards, tom lane
>