Re: How to share the result data of separated plan
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>, Hitoshi Harada <umi.tanuki@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-11-07T22:35:39Z
Lists: pgsql-hackers
On Sun, Nov 7, 2010 at 1:08 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > 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? The relevant thread is here: http://archives.postgresql.org/pgsql-hackers/2010-02/msg00783.php -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company