title: Mongodb query execution time
body: <p>I used Query below its take to much time </p>
  
  <p>Query</p>
  
  <pre><code>db.saleOrder.find({"currentStatus._id":"147"},{"_id":1}).limit(10).explain("executionStats")
  </code></pre>
  
  <p>ExecutionStats result</p>
  
  <pre><code>{
      "queryPlanner" : {
          "plannerVersion" : 1,
          "namespace" : "db_erp_tube.saleOrder",
          "indexFilterSet" : false,
          "parsedQuery" : {
              "currentStatus._id" : {
                  "$eq" : "147"
              }
          },
          "winningPlan" : {
              "stage" : "LIMIT",
              "limitAmount" : 10,
              "inputStage" : {
                  "stage" : "PROJECTION",
                  "transformBy" : {
                      "_id" : 1
                  },
                  "inputStage" : {
                      "stage" : "COLLSCAN",
                      "filter" : {
                          "currentStatus._id" : {
                              "$eq" : "147"
                          }
                      },
                      "direction" : "forward"
                  }
              }
          },
          "rejectedPlans" : [ ]
      },
      "executionStats" : {
          "executionSuccess" : true,
          "nReturned" : 10,
          "executionTimeMillis" : 8673,
          "totalKeysExamined" : 0,
          "totalDocsExamined" : 3458482,
          "executionStages" : {
              "stage" : "LIMIT",
              "nReturned" : 10,
              "executionTimeMillisEstimate" : 8460,
              "works" : 3458484,
              "advanced" : 10,
              "needTime" : 3458473,
              "needYield" : 0,
              "saveState" : 27019,
              "restoreState" : 27019,
              "isEOF" : 1,
              "invalidates" : 0,
              "limitAmount" : 10,
              "inputStage" : {
                  "stage" : "PROJECTION",
                  "nReturned" : 10,
                  "executionTimeMillisEstimate" : 8450,
                  "works" : 3458483,
                  "advanced" : 10,
                  "needTime" : 3458473,
                  "needYield" : 0,
                  "saveState" : 27019,
                  "restoreState" : 27019,
                  "isEOF" : 0,
                  "invalidates" : 0,
                  "transformBy" : {
                      "_id" : 1
                  },
                  "inputStage" : {
                      "stage" : "COLLSCAN",
                      "filter" : {
                          "currentStatus._id" : {
                              "$eq" : "147"
                          }
                      },
                      "nReturned" : 10,
                      "executionTimeMillisEstimate" : 8400,
                      "works" : 3458483,
                      "advanced" : 10,
                      "needTime" : 3458473,
                      "needYield" : 0,
                      "saveState" : 27019,
                      "restoreState" : 27019,
                      "isEOF" : 0,
                      "invalidates" : 0,
                      "direction" : "forward",
                      "docsExamined" : 3458482
                  }
              }
          }
      },
      "serverInfo" : {
          "host" : "172.16.109",
          "port" : 27017,
          "version" : "4.0.0",
          "gitVersion" : "3b07af3d4f471ae89e8186d33bbb1d5259597d51"
      },
      "ok" : 1,
      "operationTime" : Timestamp(1556365275, 114),
      "$clusterTime" : {
          "clusterTime" : Timestamp(1556365275, 114),
          "signature" : {
              "hash" : BinData(0,"ppu91nKmeiC//+UvdsEbjrBTDLU="),
              "keyId" : NumberLong("6633468944474701825")
          }
      }
  }
  </code></pre>