Re: Time span conversion function

Tom Lane wrote:

>Brendan Jurd <blakjak(at)blakjak(dot)sytes(dot)net> writes:
>
>
>>Of course, it would be possible to create a shorthand version of the
>>function which expects (text, interval), and passes directly to
>>time_span($1, now(), $2).
>>
>>
>
>This bothers me a bit. That essentially says that (text, interval)
>has a hidden instability: the results depend on when you execute it.
>
>If we allow this form, it should be restricted to only those units
>(values of the text parameter) for which the result would *not*
>depend on now().
>
>
mm, I see your point. I suppose the only real reason to have the
shorthand version is for people who want to test an interval value and
don't particularly care what the startpoint is -- so they just use now()
because it's a convenient way of getting a timestamp that satisfies the
function.

To be honest, I'd be quite comfortable with dropping the shorthand
version from the proposal. If the caller has to type another 7
characters, so be it. It could fall under the "if you want it, define
your own function for it" category.

BJ