Horton

Re: [sqlsmith] Failed assertion in create_gather_path

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

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Andreas Seltenreich <seltenreich@gmx.de>, pgsql-hackers@postgresql.org
Date: 2018-04-07T18:46:08Z
Lists: pgsql-hackers 
Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> Andreas Seltenreich wrote:
>> sqlsmith found a query that triggers the following assertion in master
>> 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.

			regards, tom lane

Commits

  1. Prevent generation of bogus subquery scan paths.

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