Free MongoDB C100DEV Exam Questions

Which of the following statements correctly describes the relationship between BSON and JSON in MongoDB?

Suppose you're designing a MongoDB database for an online ticket booking system where millions of users can concurrently book tickets for various events. To maintain data consistency, you need to ensure that only one user can book a specific seat for an event at a time. Which MongoDB feature would you use to ensure data consistency in this high-concurrency situation?

How does MongoDB handle sorting on fields that contain missing values (i.e., values that are not present in all documents in the collection)?

Suppose you have a restaurants collection with the following document structure:

{

  _id: ObjectId("5eb3d668b31de5d588f42931"),

  address: {

    building: '6409',

    coord: [ -74.00528899999999, 40.628886 ],

    street: '11 Avenue',

    zipcode: '11219'

  },

  borough: 'Brooklyn',

  cuisine: 'American',

  grades: [

    {

      date: ISODate("2014-07-18T00:00:00.000Z"),

      grade: 'A',

      score: 12

    },

    {

      date: ISODate("2013-07-30T00:00:00.000Z"),

      grade: 'A',

      score: 12

    },

    {

      date: ISODate("2013-02-13T00:00:00.000Z"),

      grade: 'A',

      score: 11

    },

    { date: ISODate("2012-08-16T00:00:00.000Z"), 

      grade: 'A', 

      score: 2 },

    {

      date: ISODate("2011-08-17T00:00:00.000Z"),

      grade: 'A',

      score: 11

    }

  ],

  name: 'Regina Caterers',

  restaurant_id: '40356649'

}

You don't have any indexes so far. What will the query plan look like for the following query?

db.restaurants.find( { "cuisine": "American" } )