Re: [sqlsmith] Parallel worker crash on seqscan

I wrote:
> Like Ashutosh, I can't reproduce the crash, so it's hard to speculate much
> further.

Ah-hah: now I can. The recipe lacks these important steps:

set parallel_setup_cost TO 0;
set parallel_tuple_cost TO 0;

That changes the plan to

Limit (cost=0.00..0.06 rows=1 width=64)
-> Nested Loop (cost=0.00..57.25 rows=1000 width=64)
-> Function Scan on pg_show_all_settings a (cost=0.00..10.00 rows=1000 width=64)
-> Limit (cost=0.00..0.03 rows=1 width=32)
-> Gather (cost=0.00..3.54 rows=130 width=32)
Workers Planned: 2
-> Parallel Seq Scan on pg_opclass (cost=0.00..3.54 rows=54 width=32)

so what we've got is a case where a parameter computed by the FunctionScan
(in the master) would need to be passed into the parallel workers at
runtime. Do we have code for that at all? If so where is it?

regards, tom lane