Sorting by descending elevation

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Sorting by descending population

Querying by just the elevation


db.cities.find( { population: { $gte: 2000000 }, elevation: { $gte : 1654 } } )
         .sort( { elevation: -1 } ).explain();



"winningPlan" : {
    *"stage" : "SORT",*
    "sortPattern" : { "elevation" : -1 },
    "inputStage" : {
        "stage" : "SORT_KEY_GENERATOR",
        "inputStage" : {
            "stage" : "FETCH",
            "inputStage" : {
                "stage" : "IXSCAN",
                "keyPattern" : { "population" : 1, "elevation" : 1 },
            }
        }
    }
},


• Batch and sort results in memory
• No streaming (with getMore) of results
• Data limit for sorting