Re: MERGE ... RETURNING

On 2024-Mar-13, Dean Rasheed wrote:

> On Wed, 13 Mar 2024 at 06:44, jian he <jian.universality@gmail.com> wrote:
> >
> > <synopsis>
> > [ WITH <replaceable class="parameter">with_query</replaceable> [, ...] ]
> > MERGE INTO [ ONLY ] <replaceable
> >
> > here the "WITH" part should have "[ RECURSIVE ]"
> 
> Actually, no. MERGE doesn't support WITH RECURSIVE.
> 
> It's not entirely clear to me why though. I did a quick test, removing
> that restriction in the parse analysis code, and it seemed to work
> fine. Alvaro, do you remember why that restriction is there?

There's no real reason for it, other than I didn't want to have to think
it through; I did suspect that it might Just Work, but I felt I would
have had to come up with more nontrivial test cases than I wanted to
write at the time.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"People get annoyed when you try to debug them."  (Larry Wall)