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  1. Core Server
  2. SERVER-99024

histogramCE: Estimate for $ne is zero in the presence of -Infinity , index

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

let integer_docs = [];

for (let i = 1; i < 100; i++) {
    integer_docs.push({a: i});
}

integer_docs.push({a: Number.NEGATIVE_INFINITY});

db.foo.insertMany(integer_docs);
db.foo.createIndex({a: 1});
db.foo.runCommand({analyze: "foo", key: "a"});
db.adminCommand({setParameter: 1, planRankerMode: "histogramCE"});
db.foo.find({a: {$ne: -1}}).explain();
      Show
      db.foo.drop(); let integer_docs = []; for (let i = 1; i < 100; i++) { integer_docs.push({a: i}); } integer_docs.push({a: Number .NEGATIVE_INFINITY}); db.foo.insertMany(integer_docs); db.foo.createIndex({a: 1}); db.foo.runCommand({analyze: "foo" , key: "a" }); db.adminCommand({setParameter: 1, planRankerMode: "histogramCE" }); db.foo.find({a: {$ne: -1}}).explain();

      The cardinality estimate for $ne over some values in the presence of -Infinity in the index is zero. 

      Enterprise test> db.foo.find({a: {$ne: -1}}).count();
100

Enterprise test> db.foo.find({a: {$ne: -1}}).explain().queryPlanner.winningPlan.cardinalityEstimate;
0

            Assignee:
            timour.katchaounov@mongodb.com Timour Katchaounov
            Reporter:
            philip.stoev@mongodb.com Philip Stoev
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              Created:
              Updated: