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