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From: Arseniy Mukhin <arseniy.mukhin.dev@gmail.com>
Date: Tue, 8 Jul 2025 15:40:04 +0300
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Subject: Re: amcheck support for BRIN indexes
To: =?UTF-8?Q?=C3=81lvaro_Herrera?= <alvherre@kurilemu.de>
Cc: Tomas Vondra <tomas@vondra.me>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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On Mon, Jul 7, 2025 at 3:21=E2=80=AFPM =C3=81lvaro Herrera <alvherre@kurile=
mu.de> wrote:
>
> On 2025-Jul-07, Tomas Vondra wrote:
>
> > Alvaro, what's your opinion on the introduction of the new WITHIN_RANGE=
?
> > I'd probably try to do this using the regular consistent function:
> >
> > (a) we don't need to add stuff to all BRIN opclasses to support this
> >
> > (b) it gives us additional testing of the consistent function
> >
> > (c) building a scan key for equality seems pretty trivial
> >
> > What do you think?
>
> Oh yeah, if we can build this on top of the existing primitives, then
> I'm all for that.

Thank you for the feedback! I agree with the benefits. Speaking of
(=D1=81), it seems most of the time to be really trivial to build such a
ScanKey, but not every opclass supports '=3D' operator. amcheck should
handle these cases somehow then. I see two options here. The first is
to not provide  'heap all indexed' check for such opclasses, which is
sad because even one core opclass (box_inclusion_ops) doesn't support
'=3D' operator, postgis brin opclasses don't support it too AFAICS. The
second option is to let the user define which operator to use during
the check, which, I think, makes user experience much worse in this
case. So both options look not good from the user POV as for me, so I
don't know. What do you think about it?

And should I revert the patchset to the consistent function version then?


Best regards,
Arseniy Mukhin