On 8/27/25 05:09, Dimitrios Apostolou wrote:
> On Wednesday 2025-08-27 00:54, Adrian Klaver wrote:
>
>> What are the pg_dump/pg_restore commands?
>>
>> What are the Postgres versions involved?
>>
>> Are they community versions of Postgres or something else?
>>
>> What is the depduplication program?
>>
>>
>
>
Comments in line below.
> Dump is from PostgreSQL 16, it's pg_dump writing to stdout:
>
> pg_dump -v --format=custom --compress=none --no-toast-compression --
> serializable-deferrable db_name | borg create ...
>
>
> As you can see the backup (and deduplicating) program is borgbackup.
Ok, I use BorgBackup and it is fairly forgiving of normal changes.
FYI, if you ever want to use compression check out gzip --rsyncable, I
have found it plays well with Borg. For more information see:
https://beeznest.wordpress.com/2005/02/03/rsyncable-gzip/
>
>
> Restore is in PostgreSQL 17:
>
> I first create the empty tables by running the DDL commands in version
> control to setup the database. And then I do pg_restore --data-only:
>
> pg_restore -vvvv -j 8 -U db_owner -d db_name --schema=public --
> section=data dump_file
If you are using only the --data section why not --data-only in the pg_dump?
Or is the pg_dump output used for other purposes?
>
>
> Worth noting is that the above pg_restore goes through the WAL, i.e. all
> writes are done by walwriter, not the backend directly.
Please explain the above further.
The problem occurs when you do the pg_dump after this restore, correct?
Is it the same pg_dump command as you show above?
>
> Postgres is standard open source running on own server. It has a couple
> of custom patches that shouldn't matter in this codepath.
For completeness and just in case they may affect the output what do the
patches do?
>
>
>>> Thanks in advance,
>>> Dimitris
--
Adrian Klaver
adrian.klaver@aklaver.com
