Re: pgsql: Fix an ancient oversight in libpq's handling of V3-protocol COPY

On Tue, 2008-01-15 at 18:22 -0300, Alvaro Herrera wrote:
> Simon Riggs wrote:
> > On Mon, 2008-01-14 at 18:46 +0000, Tom Lane wrote:
> > > Log Message:
> > > -----------
> > > Fix an ancient oversight in libpq's handling of V3-protocol COPY OUT mode:
> > > we need to be able to swallow NOTICE messages, and potentially also
> > > ParameterStatus messages (although the latter would be a bit weird),
> > > without exiting COPY OUT state.  Fix it, and adjust the protocol documentation
> > > to emphasize the need for this.  Per off-list report from Alexander Galler.
> >
> > My reading of this is that previously a PQgetCopyData() operation would
> > fail mysteriously because of
> >
> > i) a reload of postgresql.conf, following the setting of any of the
> > following parameters client_encoding, DateStyle, TimeZone, and
> > standard_conforming_strings.
>
> Hmm, aren't ParameterStatus messages sent just before Ready For Query?

The docs explain they can also be sent in the above case.

> > ii) any previous LISTEN command on the session running the COPY
>
> I don't think LISTEN is involved.  It's NOTICE that's a problem, not
> NOTIFY.

That's what the docs say, but Tom's patch also adds lines to handle
NOTIFY, which is what prompted the question.

--
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com