Message-ID: <119bd418-1d7a-42c7-9270-86f3b6696399@gmail.com>
Date: Thu, 16 Apr 2026 10:26:01 +0200
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Subject: Re: TRAP: failed Assert("offsets[i] > offsets[i - 1]"), File:
 "tidstore.c"
To: Masahiko Sawada <sawada.mshk@gmail.com>
Cc: PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
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From: Andrei Lepikhov <lepihov@gmail.com>
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On 16/04/2026 10:11, Masahiko Sawada wrote:
> On Thu, Apr 16, 2026 at 12:13 AM Andrei Lepikhov <lepihov@gmail.com> wrote:
> -- Random TIDs test. The offset numbers are randomized and must be --
> unique and ordered. INSERT INTO hideblocks (blockno) SELECT
> do_set_block_offsets(blkno, array_agg(DISTINCT greatest((random() *
> :maxoffset)::int, 1))::int2[]) FROM generate_series(1, 100)
> num_offsets, generate_series(1000, 1100, 1) blkno GROUP BY blkno;

Alright, I used an explicit sort in reverse order to make sure the test is
stable. I usually create modules that may change different paths, costs, and
orders, and using random can make things unpredictable. But for this specific
test, I don't see any risk.

> 
> While I agree that we need to sort the offset numbers, I think it
> would be better to make sure the offset numbers in the array to be
> sorted in a test_tidstore.sql file where required, instead of doing so
> for all cases.

I'm not sure I follow. Are you saying that do_set_block_offsets shouldn't sort
the incoming offsets? I made this change mainly to meet the
TidStoreSetBlockOffsets contract. Since this is just a simple test, performance
isn't really a concern.

-- 
regards, Andrei Lepikhov,
pgEdge