Re: Why we lost Uber as a user

On 27/07/16 05:45, Robert Haas wrote:
> On Tue, Jul 26, 2016 at 8:27 PM, Stephen Frost <sfrost@snowman.net> wrote:
>> * Joshua D. Drake (jd@commandprompt.com) wrote:
>>> Hello,
>>>
>>> The following article is a very good look at some of our limitations
>>> and highlights some of the pains many of us have been working
>>> "around" since we started using the software.
>>>
>>> https://eng.uber.com/mysql-migration/
>>>
>>> Specifically:
>>>
>>> * Inefficient architecture for writes
>>> * Inefficient data replication
>>
>> The above are related and there are serious downsides to having an extra
>> mapping in the middle between the indexes and the heap.
>>
>> What makes me doubt just how well they understood the issues or what is
>> happening is the lack of any mention of hint bits of tuple freezing
>> (requiring additional writes).
> 
> Yeah.  A surprising amount of that post seemed to be devoted to
> describing how our MVCC architecture works rather than what problem
> they had with it.  I'm not saying we shouldn't take their bad
> experience seriously - we clearly should - but I don't feel like it's
> as clear as it could be about exactly where the breakdowns happened.

There is some more detailed information in this 30-minute talk:
https://vimeo.com/145842299
-- 
Vik Fearing                                          +33 6 46 75 15 36
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support