Re: pg_upgrade and statistics

On Thu, Mar 15, 2012 at 3:15 PM, Andrew Dunstan <andrew@dunslane.net> wrote:
>
> 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?

Historically pg_statistic has been pretty static. But that seems like
a negative, not a positive -- a big part of my fear here is that it
really really needs a lot of work to improve the statistics. I *hope*
they get knocked around dramatically in each of the next few versions
to handle multi-column stats, something to replace correlation that's
more useful, custom stats functions for more data types, stats
specifically for partitioned tables, etc. I wouldn't want to see any
reason to hold back on these changes.


-- 
greg