Subject: FW:  Re: Query is running very slow......
From: Dinesh Chandra 12108 <Dinesh.Chandra@cyient.com>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
CC: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Thread-Topic: [EXTERNAL] Re: [PERFORM] Query is running very slow......
Thread-Index: AdLUr7wP8JB03M/+QSqKr/Q3/zGYkP//qewA//5lixA=
Date: Thu, 25 May 2017 12:26:54 +0000
Message-ID: <39b30cfde27a48898340a69940581727@cyient.com>
References: <3152be5a435f45649cef6bf9321beb9a@cyient.com>
 <4caed7cc-07d8-e364-78ca-7a96b9780a9d@2ndquadrant.com>
In-Reply-To: <4caed7cc-07d8-e364-78ca-7a96b9780a9d@2ndquadrant.com>
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Hi Tomas,

Please find the below input for slow query.

(a) something about the hardware it's running on
 RAM-->64 GB, CPU->40core

(b) amounts of data in the tables / databases
Database size 	:32GB
-----------------
Tables size
-----------------
Workflow.project		: 8194 byte
workflow.tool_performance	:175 MB
workflow.evidence_to_do	:580 MB

(c) EXPLAIN or even better EXPLAIN ANALYZE of the query

"GroupAggregate  (cost=3D16583736169.63..18157894828.18 rows=3D5920110 widt=
h=3D69)"
"  ->  Sort  (cost=3D16583736169.63..16714893857.43 rows=3D52463075120 widt=
h=3D69)"
"        Sort Key: tool_performance.project_id, project.project_name, tool_=
performance.step_id, (date_trunc('day'::text, tool_performance.insert_time)=
), tool_performance.user_id"
"        ->  Nested Loop  (cost=3D2.42..787115179.07 rows=3D52463075120 wid=
th=3D69)"
"              ->  Seq Scan on evidence_to_do  (cost=3D0.00..119443.95 rows=
=3D558296 width=3D0)"
"                    Filter: (status_id =3D ANY ('{15100,15150,15200,15300,=
15400,15500}'::bigint[]))"
"              ->  Materialize  (cost=3D2.42..49843.24 rows=3D93970 width=
=3D69)"
"                    ->  Hash Join  (cost=3D2.42..49373.39 rows=3D93970 wid=
th=3D69)"
"                          Hash Cond: (tool_performance.project_id =3D proj=
ect.project_id)"
"                          ->  Seq Scan on tool_performance  (cost=3D0.00..=
48078.88 rows=3D93970 width=3D39)"
"                                Filter: ((insert_time > '2017-05-01 00:00:=
00+05:30'::timestamp with time zone) AND (insert_time < '2017-05-02 00:00:0=
0+05:30'::timestamp with time zone))"
"                          ->  Hash  (cost=3D1.63..1.63 rows=3D63 width=3D3=
8)"
"                                ->  Seq Scan on project  (cost=3D0.00..1.6=
3 rows=3D63 width=3D38)"

(d) configuration of the database (work_mem, shared_buffers etc.)

work_mem =3D 32MB
shared_buffers =3D 16GB
maintenance_work_mem =3D 8GB
temp_buffers =3D 64MB
max_connections=3D2000=09

Regards,
Dinesh Chandra
|Database administrator (Oracle/PostgreSQL)| Cyient Ltd. Noida.
------------------------------------------------------------------
Mobile: +91-9953975849 | Ext 1078 |dinesh.chandra@cyient.com=20
Plot No. 7, NSEZ, Phase-II ,Noida-Dadri Road, Noida - 201 305,India.

-----Original Message-----
From: pgsql-performance-owner@postgresql.org [mailto:pgsql-performance-owne=
r@postgresql.org] On Behalf Of Tomas Vondra
Sent: 24 May, 2017 10:56 PM
To: pgsql-performance@postgresql.org
Subject: [EXTERNAL] Re: [PERFORM] Query is running very slow......

Hi,

On 5/24/17 7:04 PM, Dinesh Chandra 12108 wrote:
> Dear Expert,
>=20
> While executing the blow query, its taking too long time to fetch output.
>=20
> Could you please help to fine tune the same?
>=20

You'll have to provide far more details - the query alone is certainly not =
enough for anyone to guess why it's slow. Perhaps look at this:

     https://wiki.postgresql.org/wiki/Slow_Query_Questions

In particular, you'll have to tell us

(a) something about the hardware it's running on

(b) amounts of data in the tables / databases

(c) EXPLAIN or even better EXPLAIN ANALYZE of the query

(d) configuration of the database (work_mem, shared_buffers etc.)


regards

--=20
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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