Re: In-order pg_dump (or in-order COPY TO)

Ron Johnson <ronljohnsonjr(at)gmail(dot)com> writes:
> On Tue, Aug 26, 2025 at 6:08 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I'd expect pg_dump/pg_restore to preserve the physical row ordering,
>> simply because it doesn't do anything that would change that.

> But the rolling checksums are against a pg_dump file, not a pg_basebackup
> file.

Oh, that wasn't clear to me.

> What probably changed are table OIDs. Would that change the ordering of
> COPY data in post-restore dump files?

It would not change the order of data within any one table. There are
corner cases in which different OID assignments can cause pg_dump to
emit database objects in a different order, see this recent thread:

https://www.postgresql.org/message-id/flat/20250707192654.9e.nmisch%40google.com

regards, tom lane