Re: Option to dump foreign data in pg_dump

Laurenz Albe <laurenz.albe@cybertec.at>

From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Daniel Gustafsson <daniel@yesql.se>, Luis Carril <luis.carril@swarm64.com>
Cc: vignesh C <vignesh21@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-11-11T20:04:17Z
Lists: pgsql-hackers
On Sat, 2019-11-09 at 21:38 +0100, Daniel Gustafsson wrote:
> I took a look at this patch again today for a review of the latest version.
> While I still think it's a potential footgun due to read-only FDW's, I can see
> usecases for having it so I'm mildly +1 on adding it.

I don't feel good about this feature.
pg_dump should not dump any data that are not part of the database
being dumped.

If you restore such a dump, the data will be inserted into the foreign table,
right?  Unless someone emptied the remote table first, this will add
duplicated data to that table.
I think that is an unpleasant surprise.  I'd expect that if I drop a database
and restore it from a dump, it should be as it was before.  This change would
break that assumption.

What are the use cases of a dump with foreign table data?

Unless I misunderstood something there, -1.

Yours,
Laurenz Albe




Commits

  1. pg_dump: Allow dumping data of specific foreign servers