Classic $group ignores collation for BSON Symbol group keys

ExportXMLWordPrintableJSON

    • Type: Bug
    • Resolution: Unresolved
    • Priority: Major - P3
    • None
    • Affects Version/s: None
    • Component/s: None
    • Query Execution
    • ALL
    • None
    • None
    • None
    • None
    • None
    • None
    • None

      Classic $group (and the merging $group on mongos) ignores the collator when comparing and hashing BSON Symbol keys, so Symbols equal under the collation form separate groups.

      • Repro, standalone with internalQueryFrameworkControl: "forceClassicEngine": Symbols a and A grouped with collation {{ {locale: "en", strength: 2}

        }} return two groups instead of one.

      • Cause: Value::compare and Value::hash_combine do not apply the collator to Symbols.
      • Found while fixing SERVER-137906.

            Assignee:
            Unassigned
            Reporter:
            Evan Bergeron
            Votes:
            0 Vote for this issue
            Watchers:
            1 Start watching this issue

              Created:
              Updated: