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

On Tue, Aug 26, 2014 at 8:14 AM, Fujii Masao <masao.fujii@gmail.com> wrote:
> On Tue, Aug 19, 2014 at 6:37 PM, Rahila Syed <rahilasyed90@gmail.com> wrote:
>> Hello,
>> Thank you for comments.
>>
>>>Could you tell me where the patch for "single block in one run" is?
>> Please find attached patch for single block compression in one run.
>
> Thanks! I ran the benchmark using pgbench and compared the results.
> I'd like to share the results.
>
> [RESULT]
> Amount of WAL generated during the benchmark. Unit is MB.
>
>                 Multiple                Single
>     off            202.0                201.5
>     on            6051.0                6053.0
>     pglz            3543.0                3567.0
>     lz4            3344.0                3485.0
>     snappy            3354.0                3449.5
>
> Latency average during the benchmark. Unit is ms.
>
>                 Multiple                Single
>     off            19.1                19.0
>     on            55.3                57.3
>     pglz            45.0                45.9
>     lz4            44.2                44.7
>     snappy            43.4                43.3
>
> These results show that FPW compression is really helpful for decreasing
> the WAL volume and improving the performance.

Yeah, those look like good numbers.  What happens if you run it at
full speed, without -R?

-- 
Robert Haas
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