Re: Performance Improvement by reducing WAL for Update Operation

On Friday, January 11, 2013 11:12 PM Simon Riggs wrote:
On 11 January 2013 17:30, Amit kapila <amit(dot)kapila(at)huawei(dot)com> wrote:
> On Friday, January 11, 2013 7:59 PM Alvaro Herrera wrote:
> Simon Riggs wrote:
>> On 28 December 2012 10:21, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>>
>
>>> I was also worried about the high variance in the results. Those
>>> averages look rather meaningless. Which would be okay, I think, because
>>> it'd mean that performance-wise the patch is a wash,
>
>> For larger tuple sizes (>1000 && < 1800), the performance gain will be good.
>> Please refer performance results by me and Kyotaro-san in below links:
>
>> http://archives.postgresql.org/message-id/6C0B27F7206C9E4CA54AE035729E9C383BEAAE32@szxeml509-mbx
>> http://archives.postgresql.org/message-id/20121228.170748.90887322.horiguchi.kyotaro@lab.ntt.co.jp

>AFAICS your tests are badly variable, but as Alvaro says, they aren't
>accurate enough to tell there's a regression.

>I'll assume not and carry on.

> (BTW the rejection of the null bitmap patch because of a performance
> regression may also need to be reconsidered).

I can post detailed numbers during next commit fest.

With Regards,
Amit Kapila.