Re: Bug in date arithmetic

On Mon, Aug 24, 2009 at 02:31:35PM -0400, Tom Lane wrote:
> David Fetter <david(at)fetter(dot)org> writes:
> > He expected '-' to subtract seconds, just as '+' added them.
>
> Ah. Well, what it boils down to is that in a scenario like
>
> known_type_expr operator unknown_literal
>
> we preferentially consider unknown_literal to be of the same type as
> the other operand. But there's no timestamp plus timestamp operator
> (doesn't seem like a sensible operation to me, does it to you?),

Doesn't seem sensible to me, either.

> so there's only one possible typing of the unknown literal, and it's
> not that. Plus and minus just aren't all that symmetrical in this
> situation.

I'm thinking that the unknown literal here should just cause an error
in the case of '+'. Same with '-', for what it's worth.

Cheers,
David (There's something happening here. What is ain't exactly clear.)
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
Skype: davidfetter XMPP: david(dot)fetter(at)gmail(dot)com

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