allow using $reduce expression as accumulator in $group

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    • Query Optimization
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      If $group accepted $reduce as accumulator, it would allow expressing any and all accumulator operations that we don't have implemented.

      Proposed syntax:

      {$group:{_id:<expr>,
      g:{$reduce:{
             input:<expr>,
             initialValue:<expr>,
             in:<expr> // using "$$value" and "$$this" same as the $reduce expression
      } }
} }

              Assignee:
              [DO NOT USE] Backlog - Query Optimization
              Reporter:
              Asya Kamsky
              Votes:
              7 Vote for this issue
              Watchers:
              14 Start watching this issue

                Created:
                Updated: