Re: Prevent COPY FREEZE on Foreign tables

Thanks for the feedback!

> Instead of throwing an error, how about we turn that into a warning?
> This way, if someone is batch-importing data for multiple tables, it won’t interrupt their script that generates a COPY for each table.
> Is it better to give them a heads-up without making them modify their commands right away?

Hmm, I prefer we error out the transaction as it can be difficult
to detect a warning and the user will assume that the
transaction completed. Also, we currently error out when
copy freeze is on a parent partition, so I rather we keep
this behavior consistent.

Regards,

Sami

On Mon, Feb 3, 2025 at 7:31 PM Zhang Mingli <zmlpostgres(at)gmail(dot)com> wrote:
>
> Hi,
>
>
> Zhang Mingli
> www.hashdata.xyz
> On Feb 4, 2025 at 04:18 +0800, Sami Imseih <samimseih(at)gmail(dot)com>, wrote:
>
>
> This really does not make sense as this
> optimization cannot be applied to a remote table and it
> can give a user a false impression that it was.
>
> +1,
>
> ```
> + /*
> + * Raise an error on foreign tables as it's not possible to apply
> + * the COPY FREEZE optimization to a remote relation.
> + */
> + if (cstate->rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
> + {
> + ereport(ERROR,
> + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
> + errmsg("cannot perform COPY FREEZE on a foreign table")));
> + }
> +
> ```
> Instead of throwing an error, how about we turn that into a warning?
> This way, if someone is batch-importing data for multiple tables, it won’t interrupt their script that generates a COPY for each table.
> Is it better to give them a heads-up without making them modify their commands right away?