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

On Wed, Dec 2, 2009 at 11:08 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
> On Wed, 2009-12-02 at 10:48 -0500, Robert Haas wrote:
>> Well, that's sort of a circular argument.  If you're going to reserve
>> space with a pre-upgrade utility, you're going to need to put the
>> pre-upgrade utility into the version you want to upgrade FROM.  If we
>> wanted to be able to use a pre-upgrade utility to upgrade to 8.5, we
>> would have had to put the utility into 8.4.
>
> Don't see any need to reserve space at all.
>
> If this is really needed, we first run a script to prepare the 8.4
> database for conversion to 8.5. The script would move things around if
> it finds a block that would have difficulty after upgrade. We may be
> able to do that simple, using fillfactor, or it may need to be more
> complex. Either way, its still easy to do this when required.

I discussed the problems with this, as I see them, in the same email
you just quoted.  You don't have to agree with my analysis, of course.

...Robert