On Sun, Sep 6, 2015 at 8:25 AM, Andres Freund <andres@anarazel.de> wrote:
> On 2015-08-10 07:03:02 +0100, Simon Riggs wrote:
>> I was previously a proponent of (2) as a practical way forwards, but my
>> proposal here today is that we don't do anything further on 2) yet, and
>> seek to make progress on 5) instead.
>>
>> If 5) fails to bring a workable solution by the Jan 2016 CF then we commit
>> 2) instead.
>>
>> If Heikki wishes to work on (5), that's good. Otherwise, I think its
>> something I can understand and deliver by 1 Jan, though likely for 1 Nov CF.
>
> I highly doubt that we can get either variant into 9.6 if we only start
> to seriously review them by then. Heikki's lsn ranges patch essentially
> was a variant of 5) and it ended up being a rather complicated patch. I
> don't think using an explicit epoch is going to be that much simpler.
>
> So I think we need to decide now.
>
> My vote is that we should try to get freeze maps into 9.6 - that seems
> more realistic given that we have a patch right now. Yes, it might end
> up being superflous churn, but it's rather localized. I think around
> we've put off significant incremental improvements off with the promise
> of more radical stuff too often.
I strongly support that plan. I think it's unlikely we're going to
have something better ready in time for 9.6, and freeze maps by
themselves would bring enormous relief to many people. And the worst
thing that happens if we rip this back out again because it isn't
needed, which isn't really going to be a lot of work.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
