Date: Fri, 7 Feb 2020 14:41:14 +0100 (CET)
From: Andreas Joseph Krogh <andreas@visena.com>
To: pgsql-performance@lists.postgresql.org
Message-ID: <VisenaEmail.24.3227de9e1532616f.1701fe0f525@tc7-visena>
In-Reply-To: 
 <CADA48rE2DNh__WfU8v=CVL4wNypPXqrm_ikRDZiuahERoDCnbA@mail.gmail.com>
Subject: Re: TOAST table performance problem
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P=C3=A5 fredag 07. februar 2020 kl. 14:23:35, skrev Asya Nevra Buyuksoy <
ayisan1096@gmail.com <mailto:ayisan1096@gmail.com>>:=20

Sorry for the misunderstanding.=20
I have a table like;=20
CREATE TABLE zamazin
 (
 paramuser_id text,
 paramperson_id integer,
 paramdata json,
 paramisdeleted boolean,
 paramactiontime timestamp without time zone
 )=20
paramdata row size is 110KB and over.=20

When I execute this query like;
select * from zamazin=20
it takes 600 seconds.=20
But when analyze the query ;=20
"Seq Scan on public.zamazin (cost=3D0.00..21.77 rows=3D1077 width=3D49) (ac=
tual=20
time=3D0.008..0.151 rows=3D1077 loops=3D1)"
 " Output: paramuser_id, paramperson_id, paramdata, paramisdeleted,=20
paramactiontime"
 " Buffers: shared hit=3D11"
 "Planning time: 0.032 ms"
 "Execution time: 0.236 ms"=20
 Why the query takes a long time, I do not understand. I assume that this=
=20
relates to the TOAST structure.=20

My guess is the time is spent in the client retrieving the data, not in the=
 DB=20
itself. Are you on a slow network?=20


--=20
Andreas Joseph Krogh=20
CTO / Partner - Visena AS=20
Mobile: +47 909 56 963=20
andreas@visena.com <mailto:andreas@visena.com>=20
www.visena.com <https://www.visena.com>=20
 <https://www.visena.com>=20

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<div>P=C3=A5 fredag 07. februar 2020 kl. 14:23:35, skrev Asya Nevra Buyukso=
y &lt;<a href=3D"mailto:ayisan1096@gmail.com">ayisan1096@gmail.com</a>&gt;:=
</div>

<blockquote style=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0pt=
 0pt 0pt 0.8ex; padding-left: 1ex;">
<div dir=3D"ltr">
<div dir=3D"ltr">Sorry for the misunderstanding.
<div>I have a table like;</div>

<div>CREATE TABLE zamazin<br>
(<br>
=C2=A0 paramuser_id text,<br>
=C2=A0 paramperson_id integer,<br>
=C2=A0 paramdata json,<br>
=C2=A0 paramisdeleted boolean,<br>
=C2=A0 paramactiontime timestamp without time zone<br>
)</div>

<div>paramdata row size is 110KB and over.</div>

<div>=C2=A0</div>

<div>When I execute this query like;<br>
<b>select * from zamazin</b></div>

<div>it takes <b>600 seconds</b>.</div>

<div>But when analyze the query ;</div>

<div><b>&quot;Seq Scan on public.zamazin =C2=A0(cost=3D0.00..21.77 rows=3D1=
077 width=3D49) (actual time=3D0.008..0.151 rows=3D1077 loops=3D1)&quot;<br=
>
&quot; =C2=A0Output: paramuser_id, paramperson_id, paramdata, paramisdelete=
d, paramactiontime&quot;<br>
&quot; =C2=A0Buffers: shared hit=3D11&quot;<br>
&quot;Planning time: 0.032 ms&quot;<br>
&quot;Execution time: 0.236 ms&quot;</b></div>

<div>=C2=A0Why the query takes a long time, I do not understand. I assume=
=C2=A0that this relates to the TOAST structure.</div>
</div>
</div>
</blockquote>

<div>=C2=A0</div>

<div>My guess is the time is spent in the=C2=A0<em>client</em>=C2=A0retriev=
ing the data, not in the DB itself. Are you on a slow network?</div>

<div>=C2=A0</div>

<div class=3D"visena-email-signature" data-visena-message-id=3D"&lt;VisenaE=
mail.24.3227de9e1532616f.1701fe0f525@tc7-visena>">
<div>--
<div><span style=3D"font-family:arial,helvetica,sans-serif;"><strong>Andrea=
s Joseph Krogh</strong></span></div>

<div><span style=3D"font-family:arial,helvetica,sans-serif;">CTO / Partner<=
/span> - Visena AS</div>

<div><span style=3D"font-family:arial,helvetica,sans-serif;">Mobile: +47 90=
9 56 963</span></div>

<div><a href=3D"mailto:andreas@visena.com">andreas@visena.com</a></div>

<div><a href=3D"https://www.visena.com">www.visena.com</a></div>

<div style=3D"padding-top: 5px"><a href=3D"https://www.visena.com"><img alt=
=3D"" src=3D"cid:part_F1559105136911UDSNTT"></a></div>
</div>
</div>

<div>=C2=A0</div>
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