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  1. Core Server
  2. SERVER-95060

Queries with hash join are always replanned using multi-planner

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    • Type: Icon: Bug Bug
    • Resolution: Unresolved
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: None
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    • Query Execution
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      db.local.drop();
db.foreign.drop();

for (let i = 0; i < 10; i++) {
    assert.commandWorked(db.foreign.insertOne({localId: i}));
    for (let j = 0; j < 10; ++j) {
        for (let k = 0; k < 10; ++k) {
            assert.commandWorked(db.local.insertOne({a: i, b: j, c: i + j, foreignId: k}));
        }
    }
}

assert.commandWorked(db.local.createIndex({a: 1, c: 1}));
assert.commandWorked(db.local.createIndex({b: 1, c: 1}));
assert.commandWorked(db.local.createIndex({a: 1, b: 1}));

const pipeline = [
      {$match: {$or: [
              {a: {$gte: 9}},
              {b: {$lte: 2}},
            ]}},
      {$lookup: {
              from: "foreign",
              localField: "foreignId",
              foreignField: "localId",
              as: "foreign"
            }}
];

assert.eq(370, db.local.aggregate(pipeline).itcount());

const bigStr = new Array(1024 * 1024).toString();
for (let i = 10; i < 128; ++i) {
      db.foreign.insertOne({localId: i, data: bigStr});
}

assert.eq(370, db.local.aggregate(pipeline).itcount());
      Show
      db.local.drop(); db.foreign.drop(); for (let i = 0; i < 10; i++) { assert .commandWorked(db.foreign.insertOne({localId: i})); for (let j = 0; j < 10; ++j) { for (let k = 0; k < 10; ++k) { assert .commandWorked(db.local.insertOne({a: i, b: j, c: i + j, foreignId: k})); } } } assert .commandWorked(db.local.createIndex({a: 1, c: 1})); assert .commandWorked(db.local.createIndex({b: 1, c: 1})); assert .commandWorked(db.local.createIndex({a: 1, b: 1})); const pipeline = [ {$match: {$or: [ {a: {$gte: 9}}, {b: {$lte: 2}}, ]}}, {$lookup: { from: "foreign" , localField: "foreignId" , foreignField: "localId" , as: "foreign" }} ]; assert .eq(370, db.local.aggregate(pipeline).itcount()); const bigStr = new Array(1024 * 1024).toString(); for (let i = 10; i < 128; ++i) { db.foreign.insertOne({localId: i, data: bigStr}); } assert .eq(370, db.local.aggregate(pipeline).itcount());

      If a query uses sbe plan cache and a hash join, it will be replanned when the foreign collection is no longer eligible for hash join.

      The replanning is always done with a multi-planner that will generate a cache entry that is not pinned.

      However, if the original query was planned using a sub-planner, the plan cache entry is pinned, so when we try to updated it with a non-pinned cache entry, we will get this error:

      Works value is not present in the old cache entry

            Assignee:
            Unassigned Unassigned
            Reporter:
            ivan.fefer@mongodb.com Ivan Fefer
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              Created:
              Updated: