Re: Doc: Improve note about copying into postgres_fdw foreign tables in batch

Daniel Gustafsson <daniel@yesql.se>

From: Daniel Gustafsson <daniel@yesql.se>
To: Etsuro Fujita <etsuro.fujita@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Andrey Lepikhov <a.lepikhov@postgrespro.ru>
Date: 2023-03-22T12:13:01Z
Lists: pgsql-hackers
> On 22 Mar 2023, at 12:58, Etsuro Fujita <etsuro.fujita@gmail.com> wrote:
> 
> On Fri, Feb 17, 2023 at 5:45 PM Etsuro Fujita <etsuro.fujita@gmail.com> wrote:
>> Here is a small patch to improve the note, which was added by commit
>> 97da48246 ("Allow batch insertion during COPY into a foreign table."),
>> by adding an explanation about how the actual number of rows
>> postgres_fdw inserts at once is determined in the COPY case, including
>> a limitation that does not apply to the INSERT case.
> 
> Does anyone want to comment on this?

Patch looks good to me, but I agree with Tatsuo downthread that "similar way to
the insert case" reads better.  Theoretically the number could be different
from 1000 if MAX_BUFFERED_TUPLES was changed in the build, but that's a
non-default not worth spending time explaining.

+       the actual number of rows <filename>postgres_fdw</filename> copies at

While not the fault of this patch I find it confusing that we mix <filename>
and <literal> for marking up "postgres_fdw", the latter seemingly more correct
(and less commonly used) than <filename>.

--
Daniel Gustafsson




Commits

  1. Doc: Improve description of the "batch_size" option for postgres_fdw.

  2. Allow batch insertion during COPY into a foreign table.