Introducing other analytics methods

MongoDB provides the explain() function, which provides you a detailed procedure for the current operator. For instance, consider following command:

db.testcollection.find().sort({x: -1}).explain()

The preceding command will execute the find operator and sort the records descending from the x field. Then, the explain() function shows an output as follows:

{
    "cursor": "BasicCursor",
    "isMultiKey": false,
    "n": 100000,
    "nscannedObjects": 100000,
    "nscanned": 100000,
    "nscannedObjectsAllPlans": 100000,
    "nscannedAllPlans": 100000,
    "scanAndOrder": true,
    "indexOnly": false,
    "nYields": 1563,
    "nChunkSkips": 0,
    "millis": 406,
    "server": "mongotest:27017",
    "filterSet": false
}

In the preceding JSON format, the n field is an integer that reflects the number of affected records. Also, the indexOnly field is Boolean and returns true only when returned fields are already indexed.

Moreover, the millis field is an integer...