Horton

Re: How to share the result data of separated plan

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>
Cc: Hitoshi Harada <umi.tanuki@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-11-07T18:08:18Z
Lists: pgsql-hackers 
Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi> writes:
> On 2010-11-07 6:23 PM +0200, Tom Lane wrote:
>> Um ... why?  I thought the whole point of breaking out ModifyTable
>> as a separate node type was so that a query involving writeable CTEs
>> would still be just one plan tree.

> We tried that for 9.0 and it didn't work.  Almost all work for 9.1 has 
> been spent on creating an infrastructure for running the executor 
> separately for every WITH list element when wCTEs are present.

I guess I shoulda been paying closer attention :-(.  That really, really
seems like fundamentally the wrong direction.  What was it that was
unfixable about the other way?  If it is unfixable, should we revert
ModifyTable?

			regards, tom lane