On Wed, Oct 10, 2007 at 11:47:15AM -0400, Tom Lane wrote:
> "Marko Kreen" <markokr@gmail.com> writes:
> > IMHO the core operations are already as stable as PostgreSQL use
> > of MVCC, as the module just exports backend internal state...
>
> Well, it exports backend internal state that did not exist before 8.2
> (ie, XID epoch). So it doesn't seem all that set in stone to me.
>
> > Another thing can can be done is more compact representation for
> > txid_snapshot type, but that also won't affect core operation.
>
> That's another thing that's likely to become very much harder to change
> once it's in core. People keep threatening to produce a working
> in-place-upgrade process, and once that's reality the on-disk
> representation of core types is going to be hard to change.
Well, if that is a concern, than it's an equally big concern to have it in
contrib. If people start using it, they're not going to care about us
saying "hey, it was in contrib, why did you use it", when we earlier said
"in order do use our whiz-bang stuff, you must install from contrib". We'll
have complaints that it's too hard to install, but we won't manage to
escape from the responsibility to keep it working.
//Magnus