Re: [REVIEW] Re: Compression of full-page-writes

Hello,

>Please find attached the patch to compress FPW. 

Sorry I had forgotten to attach. Please find the patch attached.

Thank you,

Rahila Syed

From: pgsql-hackers-owner@postgresql.org [mailto:pgsql-hackers-owner@postgresql.org] On Behalf Of Rahila Syed
Sent: Monday, September 22, 2014 3:16 PM
To: Alvaro Herrera
Cc: Rahila Syed; PostgreSQL-development; Tom Lane
Subject: Re: [HACKERS] [REVIEW] Re: Compression of full-page-writes

Hello All,

 
>Well, from Rahila's point of view the patch is actually attached, but 
>she's posting from the Nabble interface, which mangles it and turns into 
>a link instead.

Yes.

>but the end result is the 
>same: to properly submit a patch, you need to send an email to the 
> mailing list, not join a group/forum from 
>some intermediary newsgroup site that mirrors the list.
 

Thank you. I will take care of it henceforth.  

Please find attached the patch to compress FPW.  Patch submitted by Fujii-san earlier in the thread is used to merge compression GUC with full_page_writes.

I am reposting the measurement numbers.

Server Specification: 
Processors:Intel® Xeon ® Processor E5-2650 (2 GHz, 8C/16T, 20 MB) * 2 nos 
RAM: 32GB 
Disk : HDWD     450GB 10K Hot Plug 2.5-inch SAS HDD * 8 nos 
1 x 450 GB SAS HDD, 2.5-inch, 6Gb/s, 10,000 rpm 

Checkpoint segments: 1024 
Checkpoint timeout: 5 mins 

pgbench -c 64 -j 64 -r -T 900 -M prepared 
Scale factor: 1000 

                                WAL generated (MB)           Throughput (tps)              Latency(ms) 
On                             9235.43                               979.03                                           65.36 
Compress(pglz)       6518.68                                1072.34                                         59.66 
Off                             501.04                                  1135.17                                        56.34 

The results show  around 30 percent decrease in WAL volume due to compression of FPW.

Thank you ,

Rahila Syed

Tom Lane wrote:
> Rahila Syed <rahilasyed.90@gmail.com> writes:
> > Please find attached patch to compress FPW using pglz compression.
>
> Patch not actually attached AFAICS (no, a link is not good enough).

Well, from Rahila's point of view the patch is actually attached, but
she's posting from the Nabble interface, which mangles it and turns into
a link instead.  Not her fault, really -- but the end result is the
same: to properly submit a patch, you need to send an email to the
pgsql-hackers@postgresql.orgmailing list, not join a group/forum from
some intermediary newsgroup site that mirrors the list.

--
Álvaro Herrera               http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services