>
> No. It'd be a wire protocol break, and even if it weren't I would not
> expect many clients to be able to deal with it. They're in the middle
> of a query cycle (for the SELECT or CALL that got you into SPI), and
> suddenly the backend asks for COPY data? What are they supposed to
> send, or where are they supposed to put it for the COPY-out case?
> There's just not provision for nesting protocol operations like that.
>
What about running a COPY directly from C - is that possible?