| From: | Rui DeSousa <rui(dot)desousa(at)icloud(dot)com> |
|---|---|
| To: | Scott Ribe <scott_ribe(at)elevated-dev(dot)com> |
| Cc: | Pgsql-admin <pgsql-admin(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: update behavior |
| Date: | 2025-06-19 17:57:20 |
| Message-ID: | 5354269F-0A69-48E6-8BFA-C118B75970C3@icloud.com |
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| Thread: | |
| Lists: | pgsql-admin |
> On Jun 19, 2025, at 1:23 PM, Scott Ribe <scott_ribe(at)elevated-dev(dot)com> 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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