Skip site navigation (1) Skip section navigation (2)

Re: Writeable CTEs and empty relations

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Marko Tiikkaja <marko(dot)tiikkaja(at)cs(dot)helsinki(dot)fi>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Writeable CTEs and empty relations
Date: 2010-02-10 21:57:51
Message-ID: 1296.1265839071@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-hackers
Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> If the executor has buried in it the assumption that the snapshot
> can't change after startup, then does that mean that we need to start
> up and shut down the executor for each subquery?

Yes, I think so.  That's the way it's always worked in the past;
see for example PortalRunMulti() and ProcessQuery().  I think trying
to change that is a high-risk, low-reward activity.

This probably means that the planner output for queries involving
writeable CTEs has to be a separate PlannedStmt per such CTE.

			regards, tom lane

In response to

Responses

pgsql-hackers by date

Next:From: Marko TiikkajaDate: 2010-02-10 22:50:48
Subject: Re: Writeable CTEs and empty relations
Previous:From: Robert HaasDate: 2010-02-10 21:35:02
Subject: Re: [PATCH] Output configuration status after ./configure run.

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group