Sergiy Zuban <s(dot)zuban(at)gmail(dot)com> writes:
> DO I need to report this as bug?
It's not a bug, but an unimplemented feature. A patch submission would be
more likely to get you somewhere. Look into contrib/postgres_fdw/deparse.c,
and add support for BooleanTest (the NullTest support is a good model).
regards, tom lane