Re: pg_upgrade and statistics

On 03/15/2012 11:03 AM, Bruce Momjian wrote:
> On Thu, Mar 15, 2012 at 08:22:24AM +0200, Peter Eisentraut wrote:
>> On ons, 2012-03-14 at 17:36 -0400, Bruce Momjian wrote:
>>> Well, I have not had to make major adjustments to pg_upgrade since 9.0,
>>> meaning the code is almost complete unchanged and does not require
>>> additional testing for each major release.  If we go down the road of
>>> dumping stats, we will need to adjust for stats changes and test this to
>>> make sure we have made the proper adjustment for every major release.
>> 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.

I haven't looked at it, but I'm wondering how hard it is going to be in 
practice?

cheers

andrew