Re: Page-level version upgrade (was: Block-level CRC checks)

On Wed, Dec 2, 2009 at 3:48 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Greg Stark <gsstark(at)mit(dot)edu> writes:
>> This whole discussion is based on assumptions which do not match my
>> recollection of the old discussion. I would suggest people go back and
>> read the emails but it's clear at least some people have so it seems
>> people get different things out of those old emails. My recollection
>> of Tom and Heikki's suggestions for Zdenek were as follows:
>
>> 1) When 8.9.0 comes out we also release an 8.8.x which contains a new
>> guc which says to prepare for an 8.9 update.
>
> Yeah, I think the critical point is not to assume that the behavior of
> the old system is completely set in stone.  We can insist that you must
> update to at least point release .N before beginning the migration
> process.  That gives us a chance to backpatch code that makes
> adjustments to the behavior of the old server, so long as the backpatch
> isn't invasive enough to raise stability concerns.

If we have consensus on that approach, I'm fine with it. I just don't
want one of the people who wants this CRC feature to go to a lot of
trouble to develop a space reservation system that has to be
backpatched to 8.4, and then have the patch rejected as too
potentially destabilizing.

...Robert