Re: libpq API incompatibility between 7.4 and 8.0

Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > According to our RELEASE_CHANGES documentation:
>
> > The major version number should be updated whenever the source of the
> > library changes to make it binary incompatible. Such changes include,
> > but are not limited to:
>
> > 1. Removing a public function or structure (or typedef, enum, ...)
>
> > 2. Modifying a public functions arguments.
>
> > 3. Removing a field from a public structure.
>
> > so while I don't think we need to update the major number for every
> > PostgreSQL major release, the removal of prog_name probably required a
> > major bump.
>
> Well, the point is that get_progname *isn't* a "public" function.
> We never advertised it as a libpq entry point.
>
> What this really brings out to me is that our development process
> doesn't impose a very strong boundary between libpq and our bundled
> client programs. If the client programs were enforced to use only the
> documented public API of libpq then we'd not be having this discussion
> --- but stuff such as libpgport support functions tends to slip by under
> the radar. IIRC we've been bitten in exactly this way at least once
> before. What I'm suggesting is that we just solve the whole class of
> problems permanently, by abandoning the assumption that we're going to
> guarantee binary compatibility across major releases. I don't think
> that promise is really buying us anything very critical.
>
> If we don't go that way, then we need to have some automatic check that
> none of the client programs are using symbols they shouldn't be from
> libpq. (Hmm ... will the existence of the Windows port help here?)

Yes, I think Win32 will help as long as we don't let bad stuff get into
libpqddll.def. The only downside I see to bumping the major number each
time is that the major number could get pretty big. Do the dynamic
library systems handle two-digit library version numbers properly?

--
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