Re: [Patch] Adding CORRESPONDING/CORRESPONDING BY to set operation

On Tue, Jul 30, 2019 at 02:43:05PM -0700, 毛瑞嘉 wrote:
> Hi,
> 
> 
> I wrote a patch for adding CORRESPONDING/CORRESPONDING BY to set operation.
> It is a task in the todo list. This is how the patch works:
> 
> 
> I modified transformSetOperationStmt() to get an intersection target list
> which is the intersection of the target lists of the left clause and right
> clause for a set operation statement (sostmt). The intersection target list
> is calculated in transformSetOperationTree() and then I modified the target
> lists of the larg and rarg of sostmt to make them equal to the intersection
> target list. Also, I also changed the target list in pstate->p_rtable in
> order to make it consistent with the intersection target list.
> 
> 
> I attached the scratch version of this patch to the email. I am not sure
> whether the method used in the patch is acceptable or not, but any
> suggestions are appreciated. I will add tests and other related things to
> the patch if the method used in this patch is acceptable.

I tried adding documentation based on what I could infer about the
behavior of this patch. Is that documentation correct?

Best,
David.
-- 
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778

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