Re: [WIP] Performance Improvement by reducing WAL for Update Operation - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: [WIP] Performance Improvement by reducing WAL for Update Operation
Date
Msg-id 001e01cd7630$609ef3b0$21dcdb10$@kapila@huawei.com
Whole thread Raw
In response to Re: [WIP] Performance Improvement by reducing WAL for Update Operation  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
From: Simon Riggs [mailto:simon@2ndQuadrant.com] 
Sent: Thursday, August 09, 2012 5:29 PM
On 9 August 2012 12:17, Amit Kapila <amit.kapila@huawei.com> wrote:

>> This optimization is to reduce the amount of WAL and definitely adding
>> anything extra will have some impact.

> Of course. The question is "How much impact?". Each tweak has
> progressively less and less gain. This isn't a binary choice.

> Squeezing the last ounce of performance at the expense of all other
> concerns is not a sensible goal, IMHO, nor do we attempt that
> elsewhere.

> Given we're making no attempt to remove full page writes, which is
> clearly the biggest source of WAL volume currently, micro optimisation
> of other factors seems unwarranted at this stage.

What I am pointing from WAL reduction is about Update operation performance
and
full-page writes doesn't have direct correlation with Update operation
except for 
a case of first time update of page after checkpoint.

With Regards,
Amit Kapila.




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