Re: libpq changes for synchronous replication

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> It doesn't feel right to always accept PQputCopyData in COPY OUT mode, 
> though. IMHO there should be a new COPY IN+OUT mode.

Yeah, I was going to make the same complaint.  Breaking basic
error-checking functionality in libpq is not very acceptable.

> It should be pretty safe to add a CopyInOutResponse message to the 
> protocol without a protocol version bump. Thoughts on that?

Not if it's something that an existing application might see.  If
it can only happen in replication mode it's OK.

Personally I think this demonstrates that piggybacking replication
data transfer on the COPY protocol was a bad design to start with.
It's probably time to split them apart.
        regards, tom lane