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

Etsuro Fujita · Etsuro Fujita · commit 0f0a7183d7d8 · 2023-03-24T12:55:00.000+09:00
Document that the actual number of rows postgres_fdw inserts at once in the COPY case is determined in a similar way to the INSERT case, but it has a restriction that does not apply to the INSERT case. Follow-up for commit 97da482. Reviewed-by: Daniel Gustafsson and Tatsuo Ishii Discussion: https://postgr.es/m/CAPmGK14NMXDMW4qK9kHUzudN9t71uvrMKPna02X6zwgQJ6E1_g%40mail.gmail.com
diff --git a/doc/src/sgml/postgres-fdw.sgml b/doc/src/sgml/postgres-fdw.sgml
@@ -437,7 +437,11 @@ OPTIONS (ADD password_required 'false');
       </para>
 
       <para>
-       This option also applies when copying into foreign tables.
+       This option also applies when copying into foreign tables.  In that case
+       the actual number of rows <filename>postgres_fdw</filename> copies at
+       once is determined in a similar way to the insert case, but it is
+       limited to at most 1000 due to implementation restrictions of the
+       <command>COPY</command> command.
       </para>
      </listitem>
     </varlistentry>
