Raimon Fernandez <coder@montx.com> writes:
> Quoted from the documentation:
> "The cancellation signal might or might not have any effect — for
> example, if it arrives after the
> backend has finished processing the query, then it will have no
> effect.
> Here I understand that maybe it will have NO effect, so postgresql
> will still sending rows and rows and rows ...
If you're too late, the backend has already sent all the rows. There's
not much we can do about data that's already in flight. There probably
won't be that much of it though, as TCP stacks don't buffer infinite
amounts of data.
regards, tom lane