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From: yudhi s <learnerdatabase99@gmail.com>
Date: Sun, 1 Feb 2026 01:16:56 +0530
Message-ID: <CAEzWdqd6LAHs+FiFeJLqDTS-QBLq6+foE1-mgBC9AXVpFmVnZg@mail.gmail.com>
Subject: Re: Top -N Query performance issue and high CPU usage
To: Adrian Klaver <adrian.klaver@aklaver.com>
Cc: pgsql-general <pgsql-general@lists.postgresql.org>
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Thank you.

>
> 1) Without even looking at the plan I'm going to say 2-VCPU and 16GB RAM
> and is insufficient resources for what you want to do.
>
>
Can you please explain a bit in detail, how much minimum VCPU and RAM will
be enough resources to suffice this requirement? and you normally do that
calculation?


> 2) You will need to provide the schema definitions for the tables involved.
>
> Do you mean table DDL or just the index definitions on the tables should
help?

Also i was trying to understand , by just looking into the "explain
analyze" output, is there any way we can tie the specific step in the plan
, which is the major contributor of the cpu resources? Such that we can
then try to fix that part rather than looking throughout the query as its
big query?

And if any suggestion to improve the TOP-N queries where the base table may
have many rows in it.

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<div dir=3D"ltr"><div>Thank you.=C2=A0</div><div class=3D"gmail_quote gmail=
_quote_container"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px=
 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
1) Without even looking at the plan I&#39;m going to say 2-VCPU and 16GB RA=
M <br>
and is insufficient resources for what you want to do.<br>
<br></blockquote><div><br></div><div>Can you please explain a bit in detail=
, how much minimum VCPU and RAM will be enough resources to suffice this re=
quirement? and you normally do that calculation?</div><div>=C2=A0</div><blo=
ckquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left=
:1px solid rgb(204,204,204);padding-left:1ex">
2) You will need to provide the schema definitions for the tables involved.=
<br><br></blockquote><div>Do you mean table DDL or just the index definitio=
ns=C2=A0on the tables should help?</div><div><br></div><div>Also i was tryi=
ng to understand , by just looking into the &quot;explain analyze&quot; out=
put, is there any way we can tie the specific step in the plan , which is t=
he major contributor of the cpu resources? Such that we can then try to fix=
 that part rather than looking throughout the query as its big query?=C2=A0=
=C2=A0</div><div><br></div><div>And if any suggestion to improve the TOP-N =
queries where the base table may have many rows in it.</div></div></div>

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