Re: How to share the result data of separated plan

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>, Hitoshi Harada <umi.tanuki@gmail.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2010-11-08T16:38:25Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Sun, Nov 7, 2010 at 1:08 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> 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

My opinion is still the same as here:
http://archives.postgresql.org/pgsql-hackers/2010-02/msg00688.php

namely, that all we should be worrying about is a tuplestore full of
RETURNING tuples.  Any other side-effects of a DML subquery should
*not* be visible to the calling query, and therefore all this argument
about snapshots and seqscan limits is beside the point.

			regards, tom lane