Re: Parallel Queries and PostGIS

On Tue, Mar 29, 2016 at 12:48 PM, Paul Ramsey <pramsey(at)cleverelephant(dot)ca> wrote:

>> On the join case, I wonder if it's possible that _st_intersects is not
>> marked parallel-safe? If that's not the problem, I don't have a
>> second guess, but the thing to do would be to figure out whether
>> consider_parallel is false for the RelOptInfo corresponding to either
>> of pd and pts, or whether it's true for both but false for the
>> joinrel's RelOptInfo, or whether it's true for all three of them but
>> you don't get the desired path anyway.
>
> _st_intersects is definitely marked parallel safe, and in fact will
> generate a parallel plan if used alone (without the operator though,
> it's impossibly slow). It's the && operator that is the issue... and I
> just noticed that the PROCEDURE bound to the && operator
> (geometry_overlaps) is *not* marked parallel safe: could be the
> problem?

Asked and answered: marking the geometry_overlaps as parallel safe
gets me a parallel plan! Now to play with costs and see how it behaves
when force_parallel_mode is not set.

P.

>
> Thanks,
>
> P