Feedback-ID: ia2694551:Fastmail
Date: Thu, 17 Nov 2022 18:47:37 +0100
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: bobocc@yahoo.com, pgsql-docs@lists.postgresql.org
Subject: Re: Merge statement
Message-ID: <20221117174737.w7jhwzarwmudolue@alvherre.pgsql>
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On 2022-Nov-17, PG Doc comments form wrote:

> The following documentation comment has been logged on the website:
> 
> Page: https://www.postgresql.org/docs/15/sql-merge.html
> Description:
> 
> From the description it looks like a single WHEN clause is accepted, which
> is definitely not true.

Hmm, the main synopsis has 

  when_clause [...]

where the [...] is there to indicate that when_clause can appear an
arbitrary number of times.

> Please let us know how many WHEN clauses are accepted for each of WNEM
> MATCHED and WHEN NOT MATCHED.

There's no specific restriction, although I didn't try to find a
limit.  I wonder what happens if you have a few hundred thousand ...
Time to experiment, I guess.

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"No deja de ser humillante para una persona de ingenio saber
que no hay tonto que no le pueda enseñar algo." (Jean B. Say)