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Message-ID: <5730b804-3544-4774-92dd-49954b720ac3@aklaver.com>
Date: Thu, 7 Nov 2024 10:04:40 -0800
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Subject: Re: About the stability of COPY BINARY data
To: Dominique Devienne <ddevienne@gmail.com>,
 Daniel Verite <daniel@manitou-mail.org>
Cc: pgsql-general@postgresql.org
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From: Adrian Klaver <adrian.klaver@aklaver.com>
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On 11/7/24 09:55, Dominique Devienne wrote:
> On Thu, Nov 7, 2024 at 6:39 PM Daniel Verite <daniel@manitou-mail.org> wrote:
>>          Dominique Devienne wrote:
>>> Also, does the code for per-type _send() and _recv() functions
>>> really change across versions of PostgreSQL? How common are
>>> instances of such changes across versions? Any examples of such
>>> backward-incompatible changes, in the past?
>>
>> For the timestamp types, I think these functions were
>> sending/expecting float8 (before version 7.3), and then float8 or
>> int64 depending on the server configuration up until 9.6, and since
>> then int64 only.
>> The same for the "time" field of the interval type.
>> There is still an "integer_datetimes" GUC reflecting this.
> 
> Thanks. So it did happen in a distant past.
> Anything below 14 is of no concern to me though.
> So again, it does sound like changes are unlikely.

Yeah that is implied by:

https://www.postgresql.org/docs/current/pgupgrade.html

"Major PostgreSQL releases regularly add new features that often change 
the layout of the system tables, but the internal data storage format 
rarely changes. "

The COPY warning is there as heads up that it is a possibility.

> 
> And I haven't seen anything not network-byte-order,
> as far architecture is concerned.
> 
> 

-- 
Adrian Klaver
adrian.klaver@aklaver.com