Re: WIP: Page space reservation (pgupgrade)

Zdenek Kotala <Zdenek(dot)Kotala(at)Sun(dot)COM> writes:
> Tom Lane napsal(a):
>> What is the point of this? We don't need it for 8.3->8.4, we aren't
>> going to back-patch such a thing into 8.2 or before (certainly not
>> before, since reloptions didn't exist before 8.2), and I would hope we
>> put in a more general solution than this for 8.4-to-later preparatory
>> fixes.

> ...
> I think This part is possible simply backported back to 8.2 and it allows
> in-place online upgrade form 8.2 to 8.4 (and indirectly from 8.1).

I would never recommend to anyone that they depend on a patch like this
for pre-upgrade conversions. It has no way to guarantee that all pages
in the database have been fixed. And in any case, I would vote against
back-patching such a thing into 8.2, at least not without a whole lot
more field testing than it is likely to get.

As for planning that there will someday be 8.1->8.2 or even 8.2->8.3
online upgrade, I suggest that you quit wasting your time even thinking
about that. It won't happen and expending more cycles on it is mostly
going to ensure that the entire upgrade project fails. What we need now
is something that works for 8.3->8.4 and that we can extend and maintain
for future version updates.

regards, tom lane