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.
Q 1 - Which of the following is correct explanation of MongoDB processes?
A - mongod.exe is the shell process and mongo.exe is the actual database process
B - mongo.exe is the shell process and mongod.exe is the actual database process
C - mongos.exe is the MongoDB server process needed to run database
D - mongodump.exe can be used to import database backup dump
Answer : B
Explanation
The core components in the MongoDB package are: mongod, the core database process; mongos the controller and query router for sharded clusters; and mongo the interactive MongoDB Shell.
Q 2 - Which of the following replica sets vote in the election of a primary replica set?
Answer : D
Explanation
All members of a replica set, unless the value of votes is equal to 0, vote in elections. This includes all delayed, hidden and secondary-only members.
Q 3 - Which of the following commands will return all the posts with number of likes greater than 100 and less than 200, both inclusive?
A - db.posts.find({ likes : { $gt : 100, $lt : 200 } } );
B - db.posts.find({ likes : { $gte : 100, $lt : 200 } } );
C - db.posts.find({ likes : { $gt : 100 , $lte : 200 } } );
D - db.posts.find({ likes : { $gte : 100 , $lte : 200 } } );
Answer : D
Explanation
Since 100 and 200 are both inclusive, we need $gte (greater than and equal) and $lte (less than and equal).
Q 4 - What does the following query do when performed on the posts collection?
db.posts.update({_id:1},{Title:This is post with ID 1"})
A - Updates the Title of the post
B - Updating a document is possible only with $set
C - Replaces the complete document with _id as 1 with the document specified in second parameter
Answer : C
Explanation
Updating a document without using $set replaces the entire document with whatever document is specified in second parameter.
Q 5 - You can implement a multi-document transaction in MongoDB using which of the following concept?
Answer : B
Explanation
Operations on a single document are always atomic with MongoDB databases; however, operations that involve multiple documents, which are often referred to as “multi-document transactions”, are not atomic.
Q 6 - Which is the correct order (lowest to highest) in which MongoDB compares the BSON types?
A - Null, Number, String and Object
B - Number, Null, String and Object
Answer : A
Explanation
This is the defined order in which the bson types are compared. There are various other fields as per the BSON specification which can be found here: http://docs.mongodb.org/manual/reference/bson-types/
Answer : B
Explanation
The minimum number of sensible number of voting nodes 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()
Answer : A
Explanation
db.collection.getIndexes() is the correct choice.
Q 9 - In a sharded replica set environment, w defines the level and kind of write concern. Which of the following values of w specifies to return success only after a majority of voting members have acknowledged?
Answer : B
Explanation
For replica sets, if you specify the special majority value to w option, write operations will only return successfully after a majority of the voting members of the replica set have acknowledged the write operation.
Q 10 - The ________ operator limits the contents of an array field from the query results to contain only the first element matching the query condition.
Answer : B
Explanation
The $elemMatch operator limits the contents of an array field from the query results to contain only the first element matching the $elemMatch condition.
