Re: Speedup twophase transactions

On 6 September 2016 at 09:58, Stas Kelvich <s(dot)kelvich(at)postgrespro(dot)ru> wrote:
>> On 06 Sep 2016, at 04:41, Michael Paquier <michael(dot)paquier(at)gmail(dot)com> wrote:
>>
>> On Sat, Sep 3, 2016 at 10:26 PM, Michael Paquier
>> <michael(dot)paquier(at)gmail(dot)com> wrote:
>>> On Fri, Sep 2, 2016 at 5:06 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>>>> On 13 April 2016 at 15:31, Stas Kelvich <s(dot)kelvich(at)postgrespro(dot)ru> wrote:
>>>>
>>>>> Fixed patch attached. There already was infrastructure to skip currently
>>>>> held locks during replay of standby_redo() and I’ve extended that with check for
>>>>> prepared xids.
>>>>
>>>> Please confirm that everything still works on current HEAD for the new
>>>> CF, so review can start.
>>>
>>> The patch does not apply cleanly. Stas, could you rebase? I am
>>> switching the patch to "waiting on author" for now.
>>
>> So, I have just done the rebase myself and did an extra round of
>> reviews of the patch. Here are couple of comments after this extra
>> lookup.

> Oh, I was preparing new version of patch, after fresh look on it. Probably, I should
> said that in this topic. I’ve found a bug in sub transaction handling and now working
> on fix.

Not replying has wasted time and effort.

>> After review the result is attached. Perhaps a committer could get a look at it?
>
> I'll check it against my failure scenario with subtransactions and post results or updated patch here.

Make sure tests are added for that. It would have been better to say
you knew there were bugs in it earlier.

This has been buggy so far, so I am hesitant about this now. I suggest
we add significant docs to explain how it works, so everybody can
double-check the concepts. Please also do what you can to reduce the
patch complexity.

I'll look at this again in two weeks time. Help me to make sure it
gets committed that time by doing a full and complete patch. Thanks.

--
Simon Riggs http://www.2ndQuadrant.com/
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