Horton

Re: BRIN minmax multi - incorrect distance for infinite timestamp/date

Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>

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From: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2023-10-19T09:22:42Z
Lists: pgsql-hackers 
On Thu, Oct 19, 2023 at 2:31 PM Tomas Vondra
<tomas.vondra@enterprisedb.com> wrote:

>
> Does that explain the algorithm? I'm not against clarifying the comment,
> of course.

Thanks a lot for this explanation. It's clear now.

> I tried to do that, but I ran into troubles with the "date" tests. I
> needed to build values that close to the min/max values, so I did
> something like
>
> SELECT '4713-01-01 BC'::date + (i || ' days')::interval FROM
> generate_series(1,10) s(i);
>
> And then the same for the max date, but that fails because of the
> date/timestamp conversion in date plus operator.
>
> However, maybe two simple generate_series() would work ...
>

Something like this? select i::date from  generate_series('4713-02-01
BC'::date,  '4713-01-01 BC'::date, '-1 day'::interval) i;
       i
---------------
 4713-02-01 BC
 4713-01-31 BC
 4713-01-30 BC
 4713-01-29 BC
 4713-01-28 BC
 4713-01-27 BC
 4713-01-26 BC
 4713-01-25 BC
 4713-01-24 BC
 4713-01-23 BC
 4713-01-22 BC
 4713-01-21 BC
 4713-01-20 BC
 4713-01-19 BC
 4713-01-18 BC
 4713-01-17 BC
 4713-01-16 BC
 4713-01-15 BC
 4713-01-14 BC
 4713-01-13 BC
 4713-01-12 BC
 4713-01-11 BC
 4713-01-10 BC
 4713-01-09 BC
 4713-01-08 BC
 4713-01-07 BC
 4713-01-06 BC
 4713-01-05 BC
 4713-01-04 BC
 4713-01-03 BC
 4713-01-02 BC
 4713-01-01 BC
(32 rows)

-- 
Best Wishes,
Ashutosh Bapat

Commits

  1. Fix minmax-multi distance for extreme interval values

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

  3. Fix calculation in brin_minmax_multi_distance_date

  4. Fix overflow when calculating timestamp distance in BRIN