Jeff Davis <pgsql@j-davis.com> writes:
> Beyond awkwardness, one case where it matters is the interaction
> between an extension that provides hints and an extension that offers a
> CustomScan. How is the hints extension supposed to disable a path it
> doesn't know about?
This does not seem remarkably problematic to me, given Robert's
proposal of a bitmask of allowed plan types per RelOptInfo.
You just do something like
rel->allowed_plan_types = DESIRED_PLAN_TYPE;
The names of the bits you aren't setting are irrelevant to you.
regards, tom lane