Re: Which installation parts are backward compatible?

Tom Lane wrote:
> ISTM that having psql alone be cross-version-compatible will be just
> about completely uninteresting to packagers.  If we could make *all*
> the user-facing executables be cross-version, then we'd be getting
> somewhere;

Wel, I'm not so sure about the "completely uninteresting", but in any 
case the idea right now is to determine and document where we are, then 
see what's left to do, and then determine whether or how to go there.

> Looking at your list, it seems the only part of that that might not
> be within reach is that pg_dump output from version N typically
> doesn't load into server versions < N.  pg_dump is complicated enough
> without trying to make it handle that too :-(.

Yes, pg_dump certainly appears to be the major blocker.  But it might be 
doable.  I assume it would be less than or equal work to making pg_dump 
read older versions or psql support older versions.  I imagine it could 
be a GSoC project.