Horton

Re: Infinite Interval

Joseph Koshakow <koshy44@gmail.com>

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From: Joseph Koshakow <koshy44@gmail.com>
To: jian he <jian.universality@gmail.com>
Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-01-02T18:21:50Z
Lists: pgsql-hackers 
On Sat, Dec 31, 2022 at 12:09 AM jian he <jian.universality@gmail.com> wrote:
> In float8, select float8 'inf' / float8 'inf' return NaN. Now in your patch  select interval 'infinity' / float8 'infinity'; returns infinity.
> I am not sure it's right. I found this related post (https://math.stackexchange.com/questions/181304/what-is-infinity-divided-by-infinity).

Good point, I agree this should return an error. We also need to
properly handle multiplication and division of infinite intervals by
float8 'nan'. My patch is returning an infinite interval, but it should
be returning an error. I'll upload a new patch shortly.

- Joe

Commits

  1. Support +/- infinity in the interval data type.

  2. Avoid integer overflow hazard in interval_time().

  3. Guard against overflow in make_interval().

  4. Fix minmax-multi on infinite date/timestamp values

  5. Optimize various aggregate deserialization functions, take 2

  6. Remove dead code in DecodeInterval()

  7. Accept "+infinity" in date and timestamp[tz] input.

  8. Fix overflow hazards in interval input and output conversions.