const d = db.getSiblingDB("clustered_filter_slot_minimal");
d.dropDatabase();
d.createCollection("clustered", {
  clusteredIndex: { key: { _id: 1 }, unique: true, name: "c_id" },
});
d.clustered.insertOne({});
d.regular.insertOne({});

// The bound makes this a clustered scan where possible
// 'a' is a residual filter and is referenced nowhere else
// $group forces the pipeline into SBE.
const pipeline = (field) => [
  { $match: { [field]: { $gte: 0 }, a: 0 } },
  { $group: { _id: "$b" } },
];

print("------ Clustered -----");

// _id bound on a clustered collection -> clustered collection scan
print(
  d.clustered.explain().aggregate(pipeline("_id")).queryPlanner.winningPlan
    .slotBasedPlan.stages,
);

print("------ Regular -----");

// Force a collection scan by avoiding a predicate on the _id field
print(
  d.regular.explain().aggregate(pipeline("c")).queryPlanner.winningPlan
    .slotBasedPlan.stages,
);

------ Clustered -----
[3] project [s7 = newBsonObj("_id", s6)] 
[3] group [s6] [] spillSlots[] mergingExprs[] 
[3] project [s6 = (s5 ?: null)] 
[1] filter {traverseF(getField(s3, "a"), lambda(l2.0) { ((move(l2.0) == 0) ?: false) }, false)} 
[1] scan s1 = minRecordId, s2 = maxRecordId [s3 = record, s4 = recordId] [s5 = b] @"573407a8-9e56-4324-b619-45e263ca714a" forward 
------ Regular -----
[3] project [s7 = newBsonObj("_id", s6)] 
[3] group [s6] [] spillSlots[] mergingExprs[] 
[3] project [s6 = (s3 ?: null)] 
[1] filter {(traverseF(s4, lambda(l3.0) { ((move(l3.0) == 0) ?: false) }, false) && traverseF(s5, lambda(l4.0) { ((move(l4.0) >= 0) ?: false) }, false))} 
[1] scan generic [s1 = record, s2 = recordId] [s3 = b, s4 = a, s5 = c] @"0ad84926-f9a9-4d95-a035-e9e0758e92a0"