Thread

Re: Try a presorted outer path when referenced by an ORDER BY prefix

Andrei Lepikhov <lepihov@gmail.com> — 2026-05-22T05:51:04Z

On 13/05/2026 16:03, Zsolt Parragi wrote:
> +		else if (jointype == JOIN_RIGHT)
> +			ExecSetTupleBound(tuples_needed, innerPlanState(child_node));
> 
> Is this branch reachable? If I follow the code correctly, it can't
> happen with create_nestloop_path.

RIGHT NL seems like nonsense to me. This code stays here just to remind me to
add a check in the next version, if the community is interested.

> 
> pg_plan_advice also has test failures with the patch applied.

We already talked about this in the main thread for pg_plan_advice. Now, it is
unavoidable because pg_plan_advice limits optimisations that expand the planning
scope. Before, it was enough to use standard tools like create_seqscan_path and
add_path and provide a semantically correct plan. Now, every optimisation has to
meet pg_plan_advice's internal rules, which are much more restrictive.
I did not fix this test failure to highlight the unpleasant situation for
extension developers, but you can find the fix in the list [1].

[1]
https://www.postgresql.org/message-id/CAP53Pkw2Lw0bavkCR-ygmaGACBjwmY3Voq0Yhwo9rVOBWxQuyw@mail.gmail.com

-- 
regards, Andrei Lepikhov,
pgEdge