| From: | Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com> |
|---|---|
| To: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
| Cc: | Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Gavin Flower <GavinFlower(at)archidevsys(dot)co(dot)nz>, Jeff Davis <pgsql(at)j-davis(dot)com>, Andres Freund <andres(at)2ndquadrant(dot)com>, Amit Langote <amitlangote09(at)gmail(dot)com>, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>, Fabrízio Mello <fabriziomello(at)gmail(dot)com>, Thom Brown <thom(at)linux(dot)com>, Stephen Frost <sfrost(at)snowman(dot)net>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Parallel Seq Scan |
| Date: | 2015-09-18 08:03:43 |
| Message-ID: | CAJrrPGeW0iJcju=x+DprWGu9k7Xb_pj-YqcX_ooio0qg7yKQvw@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Thu, Sep 3, 2015 at 8:21 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> Attached, find the rebased version of patch.
Here are the performance test results:
Query selectivity HashAgg HashAgg
(million) + seqscan(ms) +
parallel seq scan(ms)
2
workers 4 workers 8 workers
$1 <= '001' 0.1 16717.00 7086.00
4459.00 2912.00
$1 <= '004' 0.4 17962.00 7410.00
4651.00 2977.00
$1 <= '008' 0.8 18870.00 7849.00
4868.00 3092.00
$1 <= '016' 1.5 21368.00 8645.00
6800.00 3486.00
$1 <= '030' 2.7 24622.00 14796.00 13108.00
9981.00
$1 <= '060' 5.4 31690.00 29839.00 26544.00
23814.00
$1 <= '080' 7.2 37147.00 40485.00 35763.00
32679.00
Table Size - 18GB
Total rows - 40 million
Configuration:
Shared_buffers - 12GB
max_wal_size - 5GB
checkpoint_timeout - 15min
work_mem - 1GB
System:
CPU - 16 core
RAM - 64GB
Query:
SELECT col1, col2,
SUM(col3) AS sum_col3,
SUM(col4) AS sum_col4,
SUM(col5) AS sum_col5,
SUM(col6) AS sum_col6
FROM public.test01
WHERE col1 <= $1 AND
col7 = '01' AND
col8 = '0'
GROUP BY col2,col1;
And also attached perf results for selectivity of 0.1 million and 5.4
million cases for analysis.
Regards,
Hari Babu
Fujitsu Australia
| Attachment | Content-Type | Size |
|---|---|---|
| perf_reports.zip | application/zip | 38.3 KB |
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