Re: [sqlsmith] Failed assertion in create_gather_path

Jeevan Chalke <jeevan.chalke@enterprisedb.com>

From: Jeevan Chalke <jeevan.chalke@enterprisedb.com>
To: Robert Haas <robertmhaas@gmail.com>, Andreas Seltenreich <seltenreich@gmx.de>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alvaro Herrera <alvherre@alvh.no-ip.org>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2018-04-08T07:34:02Z
Lists: pgsql-hackers

Attachments

Hi,

At some places, I have observed that we are adding a partial path even when
rel's consider_parallel is false. Due to this, the partial path added has
parallel_safe set to false and then later in create_gather_path() assertion
fails.

Attached patch to fix that.


On Sun, Apr 8, 2018 at 12:26 AM, Andreas Seltenreich <seltenreich@gmx.de>
wrote:

> Tom Lane writes:
> > Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> >> Andreas Seltenreich wrote:
> >>> as of 039eb6e92f:
> >>> TRAP: FailedAssertion("!(subpath->parallel_safe)", File:
> "pathnode.c", Line: 1813)
> >
> >> Uh, that's pretty strange -- that patch did not touch the planner at
> >> all, and the relcache.c changes are pretty trivial.
> >
> > I don't think Andreas meant that the bug is necessarily new in
> 039eb6e92f,
> > only that that's the version he happened to be testing.
>
> Right.  I'm not testing often enough yet to be able to report on commit
> granularity :-).  I'll try for a less ambiguos wording in future
> reports.
>
>


-- 
Jeevan Chalke
Technical Architect, Product Development
EnterpriseDB Corporation
The Enterprise PostgreSQL Company

Commits

  1. Prevent generation of bogus subquery scan paths.

  2. Let Parallel Append over simple UNION ALL have partial subpaths.