Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM) - Mailing list pgsql-hackers

From Robert Haas
Subject Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM)
Date
Msg-id CA+TgmoYSjYPp2RGBgDHFJzRQzB_AheA4E8UvJboGkx8mcNc=6w@mail.gmail.com
Whole thread Raw
In response to Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM)  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM)  (Alvaro Herrera <alvherre@2ndquadrant.com>)
List pgsql-hackers
On Tue, Mar 21, 2017 at 10:01 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> I think that very wide columns and highly indexed tables are not
>> particularly unrealistic, nor do I think updating all the rows is
>> particularly unrealistic.  Sure, it's not everything, but it's
>> something.  Now, I would agree that all of that PLUS unlogged tables
>> with fsync=off is not too realistic.  What kind of regression would we
>> observe if we eliminated those last two variables?
>
> Sure, we can try that.  I think we need to try it with
> synchronous_commit = off, otherwise, WAL writes completely overshadows
> everything.

synchronous_commit = off is a much more realistic scenario than fsync = off.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



pgsql-hackers by date:

Previous
From: Amit Kapila
Date:
Subject: Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM)
Next
From: Simon Riggs
Date:
Subject: Re: [HACKERS] Logical decoding on standby