Re: [sqlsmith] Failed assertion in parallel worker (ExecInitSubPlan)

On Sun, May 22, 2016 at 9:32 PM, Andreas Seltenreich <seltenreich(at)gmx(dot)de>
wrote:
>
> Amit Kapila writes:
>
> > avoid_restricted_clause_below_gather_v1.patch
> > prohibit_parallel_clause_below_rel_v1.patch
>
> I didn't observe any parallel worker related coredumps since applying
> these. The same amount of testing done before applying them yielded
> about a dozend.
>

Thanks for verification.

> Dilip Kumar writes:
>
> > So now its clear that because of sub query pullup, we may get
expression in
> > targetlist while creating single table path list. So we need to avoid
> > parallel plan if it contains expression.
>
> This sounds like a rather heavy restriction though…
>

I think what Dilip means by above statement is to avoid parallel plan if
target list contains parallel unsafe or restricted expressions. We already
restrict generation of parallel plans if qualification for a relation
contains such expressions (refer set_rel_consider_parallel()), so this
doesn't sound to be heavy restriction.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com