Fix _id group bug with dataset that has missing value or null value for _id fieldpath

XMLWordPrintableJSON

    • Type: Bug
    • Resolution: Fixed
    • Priority: Major - P3
    • 5.1.0-rc0
    • Affects Version/s: None
    • Component/s: None
    • None
    • Fully Compatible
    • ALL
    • Hide 
      coll.insert([\{a: null}, \{b: 1}]);

db.adminCommand(\{setParameter: 1, internalQueryEnableSlotBasedExecutionEngine: true});

coll.aggregate([\{$group: {_id: "$a"}}]);
{ "_id" : null }
{ "_id" : null }
      Show
      coll.insert([\{a: null }, \{b: 1}]); db.adminCommand(\{setParameter: 1, internalQueryEnableSlotBasedExecutionEngine: true }); coll.aggregate([\{$group: {_id: "$a" }}]); { "_id" : null } { "_id" : null }
    • QE 2021-10-04
    • None
    • None
    • None
    • None
    • None
    • None
    • None

      SBE $group returns two _id: null s for both missing value and null value for _id field path. They should be considered as a same group and return one _id: null.

       

            Assignee:
            Yoon Soo Kim (Inactive)
            Reporter:
            Yoon Soo Kim (Inactive)
            Votes:
            0 Vote for this issue
            Watchers:
            3 Start watching this issue

              Created:
              Updated:
              Resolved: