From: | Emre Hasegeli <emre(at)hasegeli(dot)com> |
---|---|
To: | Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> |
Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Álvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, Robert Haas <robertmhaas(at)gmail(dot)com>, Aleksander Alekseev <a(dot)alekseev(at)postgrespro(dot)ru>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: [HACKERS] [PATCH] Improve geometric types |
Date: | 2018-02-07 15:46:38 |
Message-ID: | CAE2gYzyUArNR1YcQ3MkqT4y-RLJhZ+Yg=nh=bnFsT6KVXJmGHw@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
> - line_eq looks too complex in the normal (not containing NANs)
> cases. We should avoid such complexity if possible.
>
> One problem here is that comparison conceals NANness of
> operands. Conversely arithmetics propagate it. We can converge
> NANness into a number. The attached line_eq() doesn that. This
> doesn't have almost no additional complexity when NAN is
> involved. I believe it qbehaves in the same way
> and shares a doubious behavior like this.
>
> =# select '{nan, 1, nan}'::line = '{nan, 2, nan}'::line;
> ?column?
> ----------
> t
>
> But probably no point in fixing(?) it.
I think we should fix it.
> The attached file contains line_eq, point_eq_point and
> circle_same. I expect that line_eq is fast but other two are
> doubious.
I haven't got an attachment.
> . . . Mmm.. The function seems broken. I posted the fix for
> the existing version is posted, and line_perp() in the attched
> file will work fine.
I am incorporating the fix you have posted to the other thread to this patch.
From | Date | Subject | |
---|---|---|---|
Next Message | Peter Eisentraut | 2018-02-07 15:50:12 | Re: Add more information_schema columns |
Previous Message | Andrey Borodin | 2018-02-07 15:46:35 | Re: New gist vacuum. |