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From: Rui DeSousa <[email protected]>
To: Scott Ribe <[email protected]>
Cc: Pgsql-admin <[email protected]>
Subject: Re: update behavior
Date: Thu, 19 Jun 2025 13:57:20 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>


> On Jun 19, 2025, at 1:23 PM, Scott Ribe <[email protected]> wrote:
> 
> I believe that if I UPDATE a row with the same values that it already has, this still dirties pages, writes the row, generates a WAL entry. There is no shortcut in the processing that's "hey, there's not really a change here, we'll just leave storage alone".
> 
> Is this correct?
> 
> 

Correct, but it can be avoided. 

No update occurs in this case:. 

update foo
  set data = ‘hello world’
where id = 33
   and data is distinct from ‘hello world’
;

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