Re: support for MERGE - Mailing list pgsql-hackers

From Justin Pryzby
Subject Re: support for MERGE
Date
Msg-id 20220801145257.GA15006@telsasoft.com
Whole thread Raw
In response to Re: support for MERGE  (Álvaro Herrera <alvherre@alvh.no-ip.org>)
Responses Re: support for MERGE
List pgsql-hackers
On Tue, Jun 14, 2022 at 11:27:06AM +0200, Álvaro Herrera wrote:
> @@ -448,9 +448,9 @@ COMMIT;
>      and execute the first one that succeeds.
>      If <command>MERGE</command> attempts an <command>INSERT</command>
>      and a unique index is present and a duplicate row is concurrently
> -    inserted, then a uniqueness violation is raised.
> -    <command>MERGE</command> does not attempt to avoid the
> -    error by executing an <command>UPDATE</command>.
> +    inserted, then a uniqueness violation error is raised;
> +    <command>MERGE</command> does not attempt to avoid such
> +    errors by evaluating <literal>MATCHED</literal> conditions.

This was a portion of a chang that was committed as ffffeebf2.

But I don't understand why this changed from "does not attempt to avoid the
error by executing an <command>UPDATE</command>." to "...by evaluating
<literal>MATCHED</literal> conditions."

Maybe it means to say "..by re-starting evaluation of match conditions".

Sorry to re-raise this 6 weeks later..

-- 
Justin



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