Horton

Re: Infinite Interval

Joseph Koshakow <koshy44@gmail.com>

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From: Joseph Koshakow <koshy44@gmail.com>
To: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-12-15T23:43:29Z
Lists: pgsql-hackers 
On Mon, Dec 12, 2022 at 8:05 AM Ashutosh Bapat
<ashutosh.bapat.oss@gmail.com> wrote:
>
> Hi Joseph,
> I stumbled upon this requirement a few times. So I started working on
> this support in my spare time as a hobby project to understand
> horology code in PostgreSQL. This was sitting in my repositories for
> more than an year. Now that I have someone else showing an interest,
> it's time for it to face the world. Rebased it, fixed conflicts.
>
> PFA patch implementing infinite interval. It's still WIP, there are
> TODOs in the code and also the commit message lists things that are
> known to be incomplete. You might want to assess expected output
> carefully

That's great! I was also planning to just work on it as a hobby
project, so I'll try and review and add updates as I find free
time as well.

> > The proposed design from the most recent thread was to reserve
> > INT32_MAX months for infinity and INT32_MIN months for negative
> > infinity. As pointed out in the thread, these are currently valid
> > non-infinite intervals, but they are out of the documented range.
>
> The patch uses both months and days together to avoid this problem.

Can you expand on this part? I believe the full range of representable
intervals are considered valid as of v15.

- Joe Koshakow

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.