Date: Mon, 13 Jan 2025 16:42:56 +0100
From: hubert depesz lubaczewski <depesz@depesz.com>
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To: =?utf-8?B?RcWfcmVmIEhhbMSxY8Sxb8SfbHU=?= <esref.halicioglu@primeit.com.tr>
Cc: "pgsql-general@lists.postgresql.org" <pgsql-general@lists.postgresql.org>
Subject: Re: About PostgreSQL Query Plan
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On Mon, Jan 13, 2025 at 05:26:09PM +0300, Eşref Halıcıoğlu wrote:
> Hello,
>  
> I have a query in PostgreSQL and I want this query to retrieve only data from the last 3 months. However, when I examine the query
> plan, I see that all partitions are listed.

Please note that your explain is for update, not select (which
"retrieve" in your mail would suggest).

> This raises a few questions in my mind:
> 
>   • Are all partitions really being accessed, or only the partitions of the last 3 months are being accessed while the other
>     partitions have to be shown in the query plan?

Not really possible to tell without reading explain *analyze*.
Potentially all. But perhaps just fewer.

Best regards,

depesz