Peter Geoghegan wrote:
In any case, third party foreign data wrappers that target other
database system will totally ignore ON CONFLICT DO NOTHING when built
against the master branch (unless they consider these questions). They
should perhaps make a point of rejecting DO NOTHING outright
postgres_fdw supports ON CONFLICT DO NOTHING, provided no inference
specification is provided. Foreign tables do not have associated
unique indexes (or exclusion constraints) as far as the optimizer is
concerned, and so Postgres does not accept an inference specification
for foreign tables -- the
