Re: pg_upgrade and statistics

Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> On 03/15/2012 11:03 AM, Bruce Momjian wrote:
>> On Thu, Mar 15, 2012 at 08:22:24AM +0200, Peter Eisentraut wrote:
>>> I think this could be budgeted under keeping pg_dump backward
>>> compatible. You have to do that anyway for each catalog change, and so
>>> doing something extra for a pg_statistic change should be too shocking.

>> Well, the big question is whether the community wants to buy into that
>> workload. It isn't going to be possible for me to adjust the statistics
>> dump/restore code based on the changes someone makes unless I can fully
>> understand the changes by looking at the patch.

> You're not the only person who could do that. I don't think this is all
> down to you. It should just be understood that if the stats format is
> changed, adjusting pg_upgrade needs to be part of the change. When we
> modified how enums worked, we adjusted pg_upgrade at the same time. That
> sort of thing seems totally reasonable to me.

Considering that no pg_dump infrastructure for this exists, much less
has ever been modified to accommodate a cross-version change, it seems
a bit presumptuous to just say "yes we're all buying into that".

If someone were to create that infrastructure, complete with the
ability to support the already-committed 9.1 to 9.2 changes, then
we would have a basis for discussing such a requirement. But until
then it's moot.

regards, tom lane