Raimon Fernandez <coder@montx.com> writes:
> It's not clear for me if I have to issue a flush or sync after each process of an extended query.
Basically, you send one of these at the points where you're going to
wait for an answer back. Sync is different from Flush in that it also
provides a resynchronization point after an error: when the backend hits
an error while processing a given message, it ignores following messages
up to the next Sync.
regards, tom lane