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  1. Core Server
  2. SERVER-58155

Equality semantics changed for double/decimal in SBE

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Details

    • Bug
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • 5.0.0-rc2
    • 5.1.0-rc0
    • None
    • Fully Compatible
    • ALL
    • Hide

      Create a collection: lookup_numeric_mixed:

      { "_id" : ObjectId("60db590cbb5709ba513cb8c9"), "a" : 5.01 } { "_id" : ObjectId("60db5914bb5709ba513cb8ca"), "a" : NumberDecimal("5.01") } { "_id" : ObjectId("60db591cbb5709ba513cb8cb"), "a" : NumberDecimal("5.0100") }

      Run the following pipeline on it:
      [
      {
      "$lookup":

      { "from": "lookup_numeric_mixed", "localField": "a", "foreignField": "a", "as": "docs" }

      },
      {
      "$project":

      { "_id": 0, "docs._id": 0 }

      }
      ]
      Observe that the results on 4.4 and 5.0rc2 are different.

      Show
      Create a collection: lookup_numeric_mixed: { "_id" : ObjectId("60db590cbb5709ba513cb8c9"), "a" : 5.01 } { "_id" : ObjectId("60db5914bb5709ba513cb8ca"), "a" : NumberDecimal("5.01") } { "_id" : ObjectId("60db591cbb5709ba513cb8cb"), "a" : NumberDecimal("5.0100") } Run the following pipeline on it: [ { "$lookup": { "from": "lookup_numeric_mixed", "localField": "a", "foreignField": "a", "as": "docs" } }, { "$project": { "_id": 0, "docs._id": 0 } } ] Observe that the results on 4.4 and 5.0rc2 are different.
    • Query Execution 2021-07-26, QE 2021-08-09, QE 2021-08-23, QE 2021-09-06, QE 2021-09-20

    Description

      In 4.4 the values: 5.01 (a double) and NumberDecimal("5.01") are not equal to each other according to $lookup with localField/foreignField. However when I tested this on 5.0rc2 they were counted as equal. This behavior did not occur on rc5. ksuarz@gmail.com suggested that this is likely due to the new SBE engine.

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          is related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-59584 Fix equality comparison in classic engine when decimal to double truncation is inexact

          • Major - P3 - Major loss of function.
          • Closed

          Activity

            People

              martin.neupauer@mongodb.com Martin Neupauer
              brian.deleonardis@mongodb.com Brian DeLeonardis (Inactive)
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                Created:
                Updated:
                Resolved: