Re: Do you know the reason for increased max latency due to xlog scaling?

From: "Andres Freund" <andres@2ndquadrant.com>
> On 2014-02-18 01:35:52 +0900, MauMau wrote:
>> For example, please see the max latencies of test set 2 (PG 9.3) and test
>> set 4 (xlog scaling with padding).  They are 207.359 and 1219.422
>> respectively.  The throughput is of course greatly improved, but I think 
>> the
>> response time should not be sacrificed as much as possible.  There are 
>> some
>> users who are sensitive to max latency, such as stock exchange and online
>> games.
>
> You need to compare both at the same throughput to have any meaningful
> comparison.

I'm sorry for my lack of understanding, but could you tell me why you think 
so?  When the user upgrades to 9.4 and runs the same workload, he would 
experience vastly increased max latency --- or in other words, greater 
variance in response times.  With my simple understanding, that sounds like 
a problem for response-sensitive users.


Regards
MauMau