Re: [sqlsmith] Failed assertion in BecomeLockGroupLeader

On Fri, Apr 29, 2016 at 12:01 PM, Andreas Seltenreich <seltenreich@gmx.de> wrote:
>
> Hi,
>
> tonight's sqlsmith run yielded another core dump:
>
> TRAP: FailedAssertion("!(MyProc->lockGroupLeader == ((void *)0))", File: "proc.c", Line: 1787)
>
> I couldn't identifiy a query for it though: debug_query_string is empty.
> Additionally, the offending query was not reported in the error context
> as it typically is for non-parallel executor crashes.
>

From callstack below, it is clear that the reason for core dump is that Gather node is pushed below another Gather node which makes worker execute the Gather node.  Currently there is no support in workers to launch another workers and ideally such a plan should not be generated.  It will be helpful if you can find the offending query or plan corresponding to it?