Feedback-ID: i0fe9450f:Fastmail
Date: Wed, 8 Jul 2026 11:17:06 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Ewan Young <kdbase.hack@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
	Corey Huinker <corey.huinker@gmail.com>
Subject: Re: Reject ill-formed range bounds histograms in
 pg_restore_attribute_stats()
Message-ID: <ak2zIgGdJfyna2-o@paquier.xyz>
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On Tue, Jul 07, 2026 at 04:13:30PM +0800, Ewan Young wrote:
> The attached patch validates the bounds histogram at import time and
> rejects an ill-formed one with a WARNING, matching the treatment of the
> other inconsistent inputs.  Because the histogram element type is a range
> for both range- and multirange-typed columns, the single check covers
> both.

I have been looking at that, and while the consequences of buggy
inputs are minor when loaded back, I don't really mind putting more
defenses to inform about that at the front of the restore functions.

Now, your patch is entirely blind about extended statistics; these can
also load histogram bounds.  The function you are introducing to
filter the inputs provided could be reused in this secondary case,
just by moving to stat_utils.c.

I am not really convinced that any of this stuff would be worth a
backpatch, even if it's non-invasive.  We don't have guards for
buggy infinite values, even if using empty or unordered bounds feels
kind of a stupid thing to do if one is a table owner.
--
Michael

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