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Thread: Fw: infinity as a date

Fw: infinity as a date

From
SZUCS Gábor
Date:
... Unless you have something like warranty dates which would be good to be
able to be compared to infinity.

I use a constant '3000-Jan-01' for this purpose, but probably any date in
the next millenium will do ;) I think Tom's suggestion for MAXINT is a
better one, except that it is yet to be implemented.

But it raises several questions:
* currently, what is MAXINT converted to date (if this conversion is
possible at all)? i.e. what's the maximum possible date?
* And what is the maximum finite timestamp? I assume there are not even the
same number of digits in the year part ;)
* Both converted to a date, would they really be equal?
* If so, would certain finite timestamps converted to date be infinite, or
vice versa?

$0.01 :)

G.
--
while (!asleep()) sheep++;

---------------------------- cut here ------------------------------
----- Original Message -----
From: "Peter Darley" <pdarley@kinesis-cem.com>
Sent: Thursday, December 12, 2002 6:41 PM


> Tom and Everyone,
> Not that I feel that I get a vote, but it seems to me that an infinite
date
> doesn't make any sense.  An interval is a measure of something (a value),
> which could be infinite, but a date is a point in time (not a value),
> similar to a location, and I don't think that the concept of an infinite
> point in time makes any more sense than an infinite street address.
> Just my $0.02.
> Thanks,
> Peter Darley
>
> -----Original Message-----
> From: pgsql-general-owner@postgresql.org
> [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Tom Lane
> Sent: Wednesday, December 11, 2002 10:35 PM
> To: Jean-Christian Imbeault
> Cc: pgsql-general
> Subject: Re: [GENERAL] infinity as a date
>
>
> Jean-Christian Imbeault <jc@mega-bucks.co.jp> writes:
> > As an aside, why is there a concept of an infinite timestamp but not one
> > for date?
>
> Purely historical, I'd imagine.  The various Postgres datatypes were
> developed at different times by different people.  Tom Lockhart perhaps
> remembers more about this particular discrepancy.
>
> If you are sufficiently annoyed, please submit patches to make DATE
> treat MAXINT and MININT as +infinity and -infinity instead of normal
> dates.  I would expect we'd accept such a patch.
>
> regards, tom lane
>
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Re: Fw: infinity as a date

From
Jean-Luc Lachance
Date:
For what it is worth:

nsd=# select abstime(int4(2^31-1));
        abstime
------------------------
 2038-01-18 22:14:07-05

Not too far in the future.
That is also when we will have the UNIX Y2038 problem... :)

JLL

SZUCS Gábor wrote:
>
> ... Unless you have something like warranty dates which would be good to be
> able to be compared to infinity.
>
> I use a constant '3000-Jan-01' for this purpose, but probably any date in
> the next millenium will do ;) I think Tom's suggestion for MAXINT is a
> better one, except that it is yet to be implemented.
>
> But it raises several questions:
> * currently, what is MAXINT converted to date (if this conversion is
> possible at all)? i.e. what's the maximum possible date?
> * And what is the maximum finite timestamp? I assume there are not even the
> same number of digits in the year part ;)
> * Both converted to a date, would they really be equal?
> * If so, would certain finite timestamps converted to date be infinite, or
> vice versa?
>
> $0.01 :)
>
> G.
> --
> while (!asleep()) sheep++;
>
> ---------------------------- cut here ------------------------------
> ----- Original Message -----
> From: "Peter Darley" <pdarley@kinesis-cem.com>
> Sent: Thursday, December 12, 2002 6:41 PM
>
> > Tom and Everyone,
> > Not that I feel that I get a vote, but it seems to me that an infinite
> date
> > doesn't make any sense.  An interval is a measure of something (a value),
> > which could be infinite, but a date is a point in time (not a value),
> > similar to a location, and I don't think that the concept of an infinite
> > point in time makes any more sense than an infinite street address.
> > Just my $0.02.
> > Thanks,
> > Peter Darley
> >
> > -----Original Message-----
> > From: pgsql-general-owner@postgresql.org
> > [mailto:pgsql-general-owner@postgresql.org]On Behalf Of Tom Lane
> > Sent: Wednesday, December 11, 2002 10:35 PM
> > To: Jean-Christian Imbeault
> > Cc: pgsql-general
> > Subject: Re: [GENERAL] infinity as a date
> >
> >
> > Jean-Christian Imbeault <jc@mega-bucks.co.jp> writes:
> > > As an aside, why is there a concept of an infinite timestamp but not one
> > > for date?
> >
> > Purely historical, I'd imagine.  The various Postgres datatypes were
> > developed at different times by different people.  Tom Lockhart perhaps
> > remembers more about this particular discrepancy.
> >
> > If you are sufficiently annoyed, please submit patches to make DATE
> > treat MAXINT and MININT as +infinity and -infinity instead of normal
> > dates.  I would expect we'd accept such a patch.
> >
> > regards, tom lane
> >
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> >
> >
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