| From: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
|---|---|
| To: | Marcos Pegoraro <marcos(at)f10(dot)com(dot)br> |
| Cc: | pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: update with no changes |
| Date: | 2021-11-19 16:45:18 |
| Message-ID: | CAKFQuwbxNfRB0qSrp_Tjb0hZxXiozHMPdvY585GpsUWtrSu6xA@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Fri, Nov 19, 2021 at 9:38 AM Marcos Pegoraro <marcos(at)f10(dot)com(dot)br> wrote:
> If nothing was changed, why create a new record, append data to wal, set
> old record as deleted, etc, etc ?
>
Because it takes resources to determine that nothing changed. If you want
to opt-in into that there is even an extension trigger that makes doing so
fairly simple. But it's off by default because the typical case is that
people don't frequently perform no-op updates so why eat the expense.
David J.
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