Petr Jelinek <petr.jelinek@2ndquadrant.com> writes:
> On 05/05/17 06:50, Tom Lane wrote:
>> Actually, looking around a bit there, it's not even clear why
>> we should be booby-trapping the value of an unchanged column in
>> the first place. So I'd say that not only is the code dubious
>> but the comment is inadequate too.
> Hmm, as far as I can recollect this is just leftover debugging code that
> was intended to help ensure that we are checking the "changed"
> everywhere we are supposed to (since I changed handling of these
> structured quite a bit during development). Should be changed to NULL,
> that's what we usually do in this type of situation.
So the comment should be something like "if the column is unchanged,
we should not attempt to access its value beyond this point. To
help catch any such attempts, set the string to NULL" ?
regards, tom lane