On 14 July 2011 08:16, Robert Haas <robertmh...@gmail.com> wrote: > On Jul 13, 2011, at 4:21 PM, Brendan Jurd <dire...@gmail.com> wrote: >> Well, for example, how do you go about answering the question "what is >> the day-of-month of the infinite timestamp?" The question is >> nonsense; it doesn't have a defined day of month, so I think we should >> be returning NULL or throwing an error. Returning zero is definitely >> wrong. I think throwing an error is the better way to go, as the user >> probably didn't intend to ask an incoherent question. >> >> It makes sense to special-case 'epoch' because it effectively converts >> the operation into interval math; if we ask "how many seconds from >> 1970-01-01 00:00 UTC until the infinite timestamp?" the answer is >> genuinely "infinite seconds". So +1 for the proposed change for >> epoch, and let's throw an error for the other date fields instead of >> returning zero. > > I'd rather we avoid throwing an error, because that sometimes forces people > who want to handle that case to use a subtransaction to catch it, which is > quite slow.
SELECT CASE WHEN isfinite(ts) THEN extract(day from ts) ELSE NULL END Cheers, BJ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
