On Sat, May 30, 2015 at 3:46 PM, Peter Geoghegan <pg@heroku.com> wrote:
>> What, in this release, could break things badly? RLS? Grouping sets?
>> Heikki's WAL format changes? That last one sounds really scary to me;
>> it's painful if not impossible to fix the WAL format in a minor
>> release.
>
> I think we actually have learned some lessons here. MultiXacts were a
> somewhat unusual case for a couple of reasons that I need not rehash.
>
> In contrast, Heikki's WAL format changes (just for example) are
> fundamentally just a restructuring to the existing format. Sure, there
> could be bugs, but I think that it's fundamentally different to the
> 9.3 MultiXact stuff, in that the MultiXact stuff appears to be
> stubbornly difficult to stabilize over months and years. That feels
> like something that is unlikely to be true for anything that made it
> into 9.5.
I hope you're right. But I don't think any of us foresaw just how bad
the MultiXact thing was likely to be either.
In fact, I think to some extent we may STILL be in denial about how bad it is.
--
Robert Haas
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