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  1. Core Server
  2. SERVER-61658

Last point TS Opt M4: sort(ts)+group(meta.a)

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    • Type: Icon: New Feature New Feature
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 6.0.0-rc0
    • Affects Version/s: None
    • Component/s: None
    • Labels:
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    • Fully Compatible

      Given this query:

      db.coll.aggregate([
   {$sort: {"ts”: 1}},
   {$group: {
     _id: "$meta.a”,
     ts: {$last: "$ts”},
     measureA: {$last: "$measureA"},
     measureB: {$last: "$measureB"}
   }}])

      and assuming an index on {meta.a:1, ts:1},

      Expand the $sort into the following to trigger the last point optimization:

      db.coll.aggregate([
   {$sort: {"meta.a":"1, "ts”: 1}},
   {$group: {
     _id: "$meta.a”,
     ts: {$last: "$ts”},
     measureA: {$last: "$measureA"},
     measureB: {$last: "$measureB"}
   }}])

            Assignee:
            ruslan.abdulkhalikov@mongodb.com Ruslan Abdulkhalikov (Inactive)
            Reporter:
            ruslan.abdulkhalikov@mongodb.com Ruslan Abdulkhalikov (Inactive)
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              Created:
              Updated:
              Resolved: