MongoDB Online Quiz



Following quiz provides Multiple Choice Questions (MCQs) related to MongoDB Framework. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Answer : C

Explanation

The skip and limit functions are applies linearly and hence it will first skip documents 1-5, and then return documents 6-10.

Q 2 - What is the output of the following program?

A - 60 s

B - 100 ms

C - 1 s

D - 100 s

Answer : A

Explanation

In the default configuration, MongoDB writes data to the main data files on disk every 60 seconds.

Q 3 - Which of the following operations on a single document will operate atomically?

A - update

B - $push

C - Both a and b

D - None of the above

Answer : C

Explanation

Both the update and $push operators will operate in an atomic way.

Q 4 - Consider that you are using { upsert : true } option in your update command. Which of the following parameters will be used to determine if any new documents were inserted:

A - nMatched

B - nInserted

C - nModified

D - nUpserted

Answer : D

Explanation

The nUpserted shows the number of documents that were added during the update operation.

Q 5 - Which type of indexes does MongoDB support?

A - Compound Indexes

B - Multikey Indexes

C - Geospatial Indexes

D - All of the above

Answer : D

Explanation

MongoDB supports all of the above mentioned indexes.

Q 6 - For capped collection, cursors which do not automatically close and remain open after the client exhausts the results are called:

A - Capped Cursors

B - Tailable Cursors

C - Open Cursors

D - Indexing Cursors

Answer : B

Explanation

By default, MongoDB will automatically close a cursor when the client has exhausted all results in the cursor. However, for capped collections you may use a Tailable Cursor that remains open after the client exhausts the results in the initial cursor.

Q 7 - In a sharded replica set environment, the w Option provides ability for write concern and j Option provides ability for the data to be written on disk journal. Consider that we have a seven member replica set and we want to assure that the writes are committed to journal as well as acknowledged by at least 3 nodes. What should be the value of w?

A - 0

B - 1

C - 3

D - 7

Answer : C

Explanation

The value of w determines the writes are committed and acknowledged by some minimum number of nodes which in this case is 3.

Q 8 - Which of the following command is used to get all the indexes on a collection?

A - db.collection.getIndexes()

B - db.collection.showIndexes()

C - db.collection.findIndexes()

D - db.showIndexes()

Answer : A

Explanation

db.collection.getIndexes() is the correct choice.

Q 9 - The oplog (operations log) is a special capped collection that keeps a rolling record of all operations that modify the data stored in your databases. All the replica set members contain a copy of the oplog in the following collection:

A - oplog.rs

B - local.oplog.rs

C - <database>..oplog.rs

D - <replicasetid>.oplog.rs

Answer : B

Explanation

All replica set members contain a copy of the oplog, in the local.oplog.rs collection, which allows them to maintain the current state of the database.

Q 10 - Which of the following operator can be used to control the number of items of an array that a query returns?

A - $

B - $elemMatch

C - $slice

D - MongoDB does not support partial retrieval of items from an array

Answer : C

Explanation

The $slice operator controls the number of items of an array that a query returns.

mongodb_questions_answers.htm
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