Re: Is there a good reason we don't have INTERVAL 'infinity'?

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From: Josh Berkus <josh(at)agliodbs(dot)com>
To: PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org>
Subject: Is there a good reason we don't have INTERVAL 'infinity'?
Date: 2011-11-02 00:58:48
Message-ID: 4EB095C8.1050703@agliodbs.com
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Hackers,

Is there a reason why INTERVAL 'infinity' is not implemented? That is,
an interval which is larger than all defined intervals, and which added
to any timestamp turns it into 'infinity'.

Or is it just Round TUITs?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com


From: Brar Piening <brar(at)gmx(dot)de>
To: Josh Berkus <josh(at)agliodbs(dot)com>
Cc: PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org>
Subject: Re: Is there a good reason we don't have INTERVAL 'infinity'?
Date: 2011-11-02 05:35:33
Message-ID: 4EB0D6A5.8080205@gmx.de
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Josh Berkus wrote:
> Hackers,
>
> Is there a reason why INTERVAL 'infinity' is not implemented? That is,
> an interval which is larger than all defined intervals, and which added
> to any timestamp turns it into 'infinity'.
>
> Or is it just Round TUITs?

Probably the latter.
There is even a function |isfinite(interval)| which doesn't seem to do
anything useful.
See complaint in
http://archives.postgresql.org/message-id/200101241913.f0OJDUu45423@hub.org
Although the operation used in this complaint isn't obviously defined
there certainly are operations that are defined like infinity + infinity
= infinity.
See http://de.wikipedia.org/wiki/Unendlichkeit#Analysis
(Sorry for linking the german wikipedia - the english text is ways less
verbose on this.)

Regards,

Brar


From: kris(at)shannon(dot)id(dot)au
To: Brar Piening <brar(at)gmx(dot)de>
Cc: Josh Berkus <josh(at)agliodbs(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Is there a good reason we don't have INTERVAL 'infinity'?
Date: 2011-11-03 06:42:33
Message-ID: CAOCCkqdGJhFEzEt2DMAjyyhXp0d6BoaC9+YzoS_LqQDwV5Mc3Q@mail.gmail.com
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On 2 November 2011 16:35, Brar Piening <brar(at)gmx(dot)de> wrote:
> See http://de.wikipedia.org/wiki/Unendlichkeit#Analysis
> (Sorry for linking the german wikipedia - the english text is ways less
> verbose on this.)

Google Translate has come a very long way.

I can read that whole section easily with my brain automatically
fixing up the few grammatical errors that Google doesn't get
quite right.


From: Bruce Momjian <bruce(at)momjian(dot)us>
To: Brar Piening <brar(at)gmx(dot)de>
Cc: Josh Berkus <josh(at)agliodbs(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Is there a good reason we don't have INTERVAL 'infinity'?
Date: 2011-11-10 19:28:38
Message-ID: 201111101928.pAAJScl10637@momjian.us
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Brar Piening wrote:
>
> Josh Berkus wrote:
> > Hackers,
> >
> > Is there a reason why INTERVAL 'infinity' is not implemented? That is,
> > an interval which is larger than all defined intervals, and which added
> > to any timestamp turns it into 'infinity'.
> >
> > Or is it just Round TUITs?
>
> Probably the latter.
> There is even a function |isfinite(interval)| which doesn't seem to do
> anything useful.
> See complaint in
> http://archives.postgresql.org/message-id/200101241913.f0OJDUu45423@hub.org
> Although the operation used in this complaint isn't obviously defined
> there certainly are operations that are defined like infinity + infinity
> = infinity.
> See http://de.wikipedia.org/wiki/Unendlichkeit#Analysis
> (Sorry for linking the german wikipedia - the english text is ways less
> verbose on this.)

TODO has:

Allow infinite intervals just like infinite timestamps

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +