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  1. Core Server
  2. SERVER-104101

SBE hash intersection can miss documents

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    • Type: Icon: Bug Bug
    • Resolution: Unresolved
    • Priority: Icon: Major - P3 Major - P3
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    • Affects Version/s: None
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    • Query Execution
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      const coll = db.coll;
coll.drop()
assert.commandWorked(db.adminCommand({
    setParameter: 1,
    internalQueryForceIntersectionPlans: 1,
    internalQueryPlannerEnableHashIntersection: 1,
    internalQueryFrameworkControl: 'trySbeEngine'
}));
assert.commandWorked(coll.insert({
    _id: 0,
    a: 0
}))

const query = [
    {
        $match: {
            a: {$exists: true},
            _id: {$exists: true},
            $or: [{a: 0}, {a: {$ne: 1}}]
        }
    },
    {$sort: {a: 1}}
];
jsTestLog(coll.aggregate(query).toArray())
// 1 document, the correct result
assert.commandWorked(coll.createIndex({_id: 1, a: 1}))
jsTestLog(coll.aggregate(query).toArray())
// Hashed intersection plan - No results
      Show
      const coll = db.coll; coll.drop() assert .commandWorked(db.adminCommand({ setParameter: 1, internalQueryForceIntersectionPlans: 1, internalQueryPlannerEnableHashIntersection: 1, internalQueryFrameworkControl: 'trySbeEngine' })); assert .commandWorked(coll.insert({ _id: 0, a: 0 })) const query = [ { $match: { a: {$exists: true }, _id: {$exists: true }, $or: [{a: 0}, {a: {$ne: 1}}] } }, {$sort: {a: 1}} ]; jsTestLog(coll.aggregate(query).toArray()) // 1 document, the correct result assert .commandWorked(coll.createIndex({_id: 1, a: 1})) jsTestLog(coll.aggregate(query).toArray()) // Hashed intersection plan - No results
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      With internalQueryPlannerEnableHashIntersection=1, internalQueryForceIntersectionPlans=1, and internalQueryFrameworkControl=trySbeEngine, the repro below shows that an SBE hash intersection plan can miss documents.

            Assignee:
            Unassigned Unassigned
            Reporter:
            matt.boros@mongodb.com Matt Boros
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              Created:
              Updated: