Subject: Re: GSOC 2018 Project - A New Sorting Routine
To: Kefan Yang <starordust@gmail.com>
Cc: Andrey Borodin <x4mmm@yandex-team.ru>, Peter Geoghegan <pg@bowt.ie>,
 "alvherre@2ndquadrant.com" <alvherre@2ndquadrant.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Message-ID: <fbfd760c-2c6d-e38d-86dc-c58b8b0304e3@2ndquadrant.com>
Date: Tue, 24 Jul 2018 17:16:03 +0200
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On 07/24/2018 12:21 AM, Kefan Yang wrote:
> Hi Tomas!
> 
> I did a few tests on my own Linux machine, but the problem is that my 
> resources on AWS(CPU, RAM and even Disk space) are very limited. I 
> considered establishing virtual machine on my own PC but the performance 
> is even worse.
> 
> My original patch has two main optimizations: (1) switch to heap sort 
> when depth limit exceeded (2) check whether the array is presorted only 
> once at the beginning. Now I want to test these optimizations 
> separately. On AWS EC2 instance, regressions on CREATE INDEX cases seems 
> to be less significant if we use (1) only, but I can only test up to 
> 100000 records and 512MB memory using your scripts.
> 
> So would you mind re-running the tests using the two patches I provided 
> in the attachment? That will be very helpful
> 

I can do that, but it'll have to wait a couple of days. I'm currently 
using the boxes for some other tests.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services