Re: Allow logical replication to copy tables in binary format

(1) create_subscription.sgml

+          column types as opposed to text format. Even when this option is enabled,
+          only data types having binary send and receive functions will be
+          transferred in binary. Note that the initial synchronization requires

(1-1)

I think it's helpful to add a reference for the description about send and receive functions (e.g. to the page of CREATE TYPE).

(1-2)

Also, it would be better to have a cross reference from there to this doc as one paragraph probably in "Notes". I suggested this, because send and receive functions are described as "optional" there and missing them leads to error in the context of binary table synchronization.

(3) copy_table()

+       /*
+        * If the publisher version is earlier than v14, it COPY command doesn't
+        * support the binary option.
+        */

This sentence doesn't look correct grammatically. We can replace "it COPY command" with "subscription" for example. Kindly please fix it.