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Re: Remove restrictions in recursive query

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Renan Alves Fonseca <renanfonseca@gmail.com>
Cc: pgsql-hackers@postgresql.org
Date: 2025-03-27T16:39:55Z
Lists: pgsql-hackers 
On Thu, Mar 27, 2025 at 12:37 PM Robert Haas <robertmhaas@gmail.com> wrote:
> It's not a problem if UNION ALL is used within the initial_query and
> it's not a problem if UNION ALL is used within the iterated_query. But
> you can't apply ORDER BY to the result of the UNION, because the UNION
> is kind of fake -- we're not running the UNION as a single query,
> we're running the two halves separately, the first once and the second
> as many times as needed.

Oops. The two UNION ALL references in the first part of this paragraph
should have said ORDER BY.

-- 
Robert Haas
EDB: http://www.enterprisedb.com