Re: Merge statement

Hello!Thank you. I was fooled by the fact that sometimes it is marked with [...] and other times with [,...]
I think that consistency might worth attention, since [...] may indicate "anything", while [,...] are more likely to indicate a specific thing that may be repeated.
Best regards, Cristi Boboc

On Thursday, November 17, 2022 at 07:47:41 PM GMT+2, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:

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)