Re: eXtensible Transaction Manager API (v2)

On Fri, Mar 11, 2016 at 1:11 PM, David Steele <david(at)pgmasters(dot)net> wrote:
> On 2/10/16 12:50 PM, Konstantin Knizhnik wrote:
>> PostgresProffesional cluster teams wants to propose new version of
>> eXtensible Transaction Manager API.
>> Previous discussion concerning this patch can be found here:
>>
>> http://www.postgresql.org/message-id/F2766B97-555D-424F-B29F-E0CA0F6D1D74@postgrespro.ru
>
> I see a lot of discussion on this thread but little in the way of consensus.
>
>> The API patch itself is small enough, but we think that it will be
>> strange to provide just API without examples of its usage.
>
> It's not all that small, though it does apply cleanly even after a few
> months. At least that indicates there is not a lot of churn in this area.
>
> I'm concerned about the lack of response or reviewers for this patch.
> It may be because everyone believes they had their say on the original
> thread, or because it seems like a big change to go into the last CF, or
> for other reasons altogether.
>
> I think you should try to make it clear why this patch would be a win
> for 9.6.
>
> Is anyone willing to volunteer a review or make an argument for the
> importance of this patch?

There's been a lot of discussion on another thread about this patch.
The subject is "The plan for FDW-based sharding", but the thread kind
of got partially hijacked by this issue. The net-net of that is that
I don't think we have a clear enough idea about where we're going with
global transaction management to make it a good idea to adopt an API
like this. For example, if we later decide we want to put the
functionality in core, will we keep the hooks around for the sake of
alternative non-core implementations? I just don't believe this
technology is nearly mature enough to commit to at this point.

Konstantin does not agree with my assessment, perhaps unsurprisingly.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company