Re: Will libpq 8 PQ*cancel functions work with 7.4 servers?

Hi,

On 6/13/05, Piotr Sulecki <Piotr(dot)Sulecki(at)sybilla(dot)traxelektronik(dot)pl> wrote:
> Volkan YAZICI napisał(a):
> >>My question is, will the new interface (PQgetCancel / PQcancel /
> >>PQfreeCancel) work with the version 7.4 server?
> >
> > AFAIC, no.
>
> That would mean it was a protocol change as well as an API change.
> If the protocol was unchanged, the new API would generate the same
> link-level events, only in a different way. And I seem to recall reading
> somewhere that version 8.0 uses the same link-level protocol for
> client-to-backend communication as 7.4 did. What you say contradicts it.

Sorry, I get your question wrong. You're right. There isn't a new
protocol update in related patch. It just creates a more efficient
form for cancel operation. Furthermore, as you can see from the
documentation, you're still able to use obsolete PQrequestCancel()
function with same protocol.

But, as I see from patching date, new code is available only in 8.0
releases. You need to patch your 7.4 libpq library for similar
functionality. (I didn't try it but it should work when you try patch
related source files.) Or, you may use a new libpq with old 7.4
server.

Regards.

P.S. I hope, I didn't miss anything this time :)