Re: [HACKERS] postgres_fdw: Add support for INSERT OVERRIDING clause

On Wed, Nov 29, 2017 at 8:12 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> IIRC, this issue was debated at great length back when we first put
> in foreign tables, because early drafts of postgres_fdw did what you
> propose here, and we ran into very nasty problems.  We eventually decided
> that allowing remotely-determined column defaults was a can of worms we
> didn't want to open.  I do not think that GENERATED columns really change
> anything about that.  They certainly don't do anything to resolve the
> problems we were contending with back then.  (Which I don't recall the
> details of; you'll need to trawl the archives.  Should be somewhere early
> in 2013, though, since we implemented that change in commit 50c19fc76.)

So this gives a good reason to do nothing or return an error at
postgres_fdw level for OVERRIDING?
-- 
Michael