Re: [SQL] Interval subtracting

Bruce Momjian wrote:
> Even if we had people do:
>
> justify_hours(justify_days(justify_hours()))
>
> I don't think that would do what we want in all cases. Consider '1 mon
> -1 hour'. That should be '29 days 23 hours' but neither existing
> function, even if modified, will allow us to return that. Only
> something like justify_interval() could do it.
>

justify_days(justify_hours(...)) fixes *everything* in the most recently
submitted patch, regardless of the convoluted case you invent. There is no data
for which it won't work. There is no need for justify_interval(...), except as
syntactic sugar.

Since the backward compatibility argument didn't convince you, then we should go
with the existing patch as-is. Whether we introduce the new function
justify_interval(...) could be treated as a separate question, though I don't
mind putting that in the patch and resubmitting.

mark