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

On Tue, Aug 26, 2025 at 12:43 PM Dimitrios Apostolou <jimis@gmx.net> wrote:

> Could the
> row-order have changed when doing COPY FROM with pg_restore?


There is no reliable, meaningful, row ordering when it comes to the
physical files.  Sure, cluster does make an attempt, but it is quite
limited in practice.


> A *logical* dump of data shouldn't be affected by on-disk order.
> Internal representation shouldn't affect the output.
>

The logical dump has no ordering - it will come out however it comes out.
"COPY <table> TO ..." doesn't have an order by clause - there is no way to
make or communicate to it that ordering is important.  For adhoc work you
can use "COPY <query> TO ..." and put and order by in the query.

David J.