Re: unclear syntax explanation for multiple window definitions in a SELECT query

On Thu, Feb 16, 2023 at 5:13 AM PG Doc comments form <noreply(at)postgresql(dot)org>
wrote:

> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/15/sql-select.html
> Description:
>
> The syntax documentation for SELECT in SQL COMMANDS section is unclear in
> explaining how to use multiple window definitions. It's easy to read it
> and
> believe that multiple WINDOW keywords, one for each definition, are
> correct,
> which is not the case.
>
> See this stackoverflow question and answer on point:
>
> https://stackoverflow.com/questions/59651529/multiple-named-windows-in-a-postgres-query
>
>
This is how we've chosen to document this kind of grammar and I don't see a
compelling reason to revisit that decision on the basis of this report. I
could consider some additional wording regarding "each clause keyword only
ever appears once in a given (sub)query" though that seems almost
self-evident as part of the learning of SQL. The fact that you write
WINDOW and then a comma-separated listing of names plus definitions is how
that syntax diagram is read, just like with WITH, FROM, and GROUP BY
clauses in the same diagram.

David J.