Igor,
I reduced the value of random_page_cost to 4 but the read speed remains low.
Regarding effective_cache_size and shared_buffer, do you mean they should
be both equal to 64GB?
Thanks for suggestions!
Charles
On Mon, Jul 10, 2017 at 8:35 PM, Igor Neyman wrote:
>
>
>
Jeff,
I used fio in a quick benchmarking script inspired by
https://smcleod.net/benchmarking-io/:
#!/bin/bash
#Random throughput
echo "Random throughput"
sync
fio --randrepeat=1 --ioengine=libaio --direct=1 --gtod_reduce=1 --name=test
--filename=test --bs=4M --iodepth=256 --size=10G
After reducing random_page_cost to 4 and testing more, I can report that
the aggregate read throughput for parallel sequential scan is about 90MB/s.
However the throughput for sequential scan is still around 4MB/s.
One more question: if a query uses more than one table, can more than one
table be
From: pgsql-performance-ow...@postgresql.org
[mailto:pgsql-performance-ow...@postgresql.org] On Behalf Of Igor Neyman
Sent: Tuesday, July 11, 2017 10:34 AM
To: Charles Nadeau
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Very poor read performance, query
From: Charles Nadeau [mailto:charles.nad...@gmail.com]
Sent: Tuesday, July 11, 2017 6:43 AM
To: Igor Neyman
Cc: Andreas Kretschmer ;
pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Very poor read performance, query independent
Igor,
I
Rick,
I applied the change you recommended but it didn't speed up the reads.
One thing I forgot to mention earlier is the speed of the backup made with
the COPY operations seems almost normal: I have read speed of up to 85MB/s.
Thanks for your help!
Charles
On Mon, Jul 10, 2017 at 5:25 PM, Rick
Igor,
The sum of effective_cache_size and shared_buffer will be higher than the
physical memory I have. Is it OK?
Thanks!
Charles
On Tue, Jul 11, 2017 at 4:34 PM, Igor Neyman wrote:
>
>
> *From:* Charles Nadeau [mailto:charles.nad...@gmail.com]
> *Sent:* Tuesday, July
From: Charles Nadeau [mailto:charles.nad...@gmail.com]
Sent: Tuesday, July 11, 2017 11:25 AM
To: Igor Neyman
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Very poor read performance, query independent
Attention: This email was sent from someone outside of
Thanks for the info!
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View this message in context:
http://www.postgresql-archive.org/vacuum-analyze-affecting-query-performance-tp5970681p5970830.html
Sent from the PostgreSQL - performance mailing list archive at Nabble.com.
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rverghese wrote:
> We are on Postgres 9.5, and have been running a daily vacuum analyze on the
> entire database since 8.2
> The data has grown exponentially since, and we are seeing that queries are
> now being significantly affected while the vacuum analyze runs. The query
> database is a Slony
Hmm - how are you measuring that sequential scan speed of 4MB/s? I'd
recommend doing a very simple test e.g, here's one on my workstation -
13 GB single table on 1 SATA drive - cold cache after reboot, sequential
scan using Postgres 9.6.2:
bench=# EXPLAIN SELECT count(*) FROM
On Tue, Jul 11, 2017 at 4:02 AM, Charles Nadeau
wrote:
> Jeff,
>
> I used fio in a quick benchmarking script inspired by https://smcleod.net/
> benchmarking-io/:
>
> #!/bin/bash
> #Random throughput
> echo "Random throughput"
> sync
> fio --randrepeat=1
On Tue, Jul 11, 2017 at 4:42 PM, Joshua D. Drake
wrote:
> On 07/11/2017 04:15 PM, Merlin Moncure wrote:
>
>> On Mon, Jul 10, 2017 at 9:03 AM, Charles Nadeau
>> wrote:
>>
>>> I’m running PostgreSQL 9.6.3 on Ubuntu 16.10 (kernel 4.4.0-85-generic).
On Mon, Jul 10, 2017 at 9:03 AM, Charles Nadeau
wrote:
> I’m running PostgreSQL 9.6.3 on Ubuntu 16.10 (kernel 4.4.0-85-generic).
> Hardware is:
>
> *2x Intel Xeon E5550
>
> *72GB RAM
>
> *Hardware RAID10 (4 x 146GB SAS 10k) P410i controller with 1GB FBWC (80%
> read/20%
On 07/11/2017 04:15 PM, Merlin Moncure wrote:
On Mon, Jul 10, 2017 at 9:03 AM, Charles Nadeau
wrote:
I’m running PostgreSQL 9.6.3 on Ubuntu 16.10 (kernel 4.4.0-85-generic).
Hardware is:
*2x Intel Xeon E5550
*72GB RAM
*Hardware RAID10 (4 x 146GB SAS 10k) P410i
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