On Sun, May 29, 2016 at 01:31:24AM -0400, Noah Misch wrote:
> On Sun, May 15, 2016 at 12:53:13PM +0000, Clément Prévost wrote:
> > On Mon, May 9, 2016 at 4:50 PM Andres Freund <andres@anarazel.de> wrote:
> > > I think it's a good idea to run a force-parallel run on some buildfarm
> > > members. But I'm rather convinced that the core tests run by all animals
> > > need some minimal coverage of parallel queries. Both because otherwise
> > > it'll be hard to get some coverage of unusual platforms, and because
> > > it's imo something rather relevant to test during development.
> > >
> > Good point.
> >
> > After some experiments, I found out that, for my setup (9b7bfc3a88ef7b), a
> > parallel seq scan is used given both parallel_setup_cost
> > and parallel_tuple_cost are set to 0 and given that the table is at least 3
> > times as large as the biggest test table tenk1.
> >
> > The attached patch is a regression test using this method that is
> > reasonably small and fast to run. I also hid the workers count from the
> > explain output when costs are disabled as suggested by Tom Lane and Robert
> > Haas on this same thread (
> > http://www.postgresql.org/message-id/CA+TgmobBQS4ss3+CwoZOKgbsBqKfRndwc=hLiALAep5aXQCTDA@mail.gmail.com
> > ).
> >
> > Testing under these conditions does not test the planner job at all but at
> > least some parallel code can be run on the build farm and the test suite
> > gets 2643 more lines and 188 more function covered.
> >
> > I don't know however if this test will be reliable on other platforms, some
> > more feedback is needed here.
>
> [This is a generic notification.]
>
> The above-described topic is currently a PostgreSQL 9.6 open item. Robert,
> since you committed the patch believed to have created it, you own this open
> item. If some other commit is more relevant or if this does not belong as a
> 9.6 open item, please let us know. Otherwise, please observe the policy on
> open item ownership[1] and send a status update within 72 hours of this
> message. Include a date for your subsequent status update. Testers may
> discover new open items at any time, and I want to plan to get them all fixed
> well in advance of shipping 9.6rc1. Consequently, I will appreciate your
> efforts toward speedy resolution. Thanks.
>
> [1] http://www.postgresql.org/message-id/20160527025039.GA447393@tornado.leadboat.com
I enjoy reviewing automated test patches, so I persuaded Robert to transfer
ownership of this open item to me. I will update this thread no later than
2016-06-07 09:00 UTC. There is an 85% chance I will have reviewed the
proposed patch by then.