On Fri, 3 Mar 2023 at 17:33, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> If you mean exposing PQExpBuffer to users of libpq-fe.h, I'd be very
> seriously against that. I realize that libpq exposes it at an ABI
> level, but that doesn't mean we want non-Postgres code to use it.
The code comment in the pqexpbuffer.h header suggests that client
applications are fine too use the API to:
> * This module is essentially the same as the backend's StringInfo data type,
> * but it is intended for use in frontend libpq and client applications.
I know both pg_auto_failover and pgcopydb use it quite a lot.