C100DBA Exam Questions

Consider that the posts collection contains an array called ratings which contains ratings given to the post by various users in the following format: Which of the following query...

What read preference should your application use if you want to read from the primary under normal circumstances but allow reads from secondaries when a primary is unavailable?

Given a replica set with five data-bearing members, suppose the primary goes down with operations in its oplog that have been copied from the primary to only one secondary. Assumin...

You have the following index on the toys collection: { "manufacturer" : 1, "name" : 1, "date" : -1 } Which of the following is able to use the index for the query? Check all that a...

You perform the following query on the sayings collection, which has the index { quote : "text" }: Assuming the documents below are in the collection, which ones will the following...

You perform the following operation in the shell: db.foo.insert( { } ); What gets inserted?

Dada una coleccion, cuales devuelve con la siguiente query db.coleccion.find({nombre:"ruben",apellido:"gomez"},{nombre:l,apellido:l,aficion:l});

Using an arbiter allows one to easily ensure an odd number of voters in replica sets. Why is this important?

Which of the documents below will be retrieved by the following query? Assume the documents are stored in a collection called "sample". Check all that apply. db.sample.find( { "$or...

Consider the following example document: { "_id": Objectld("5360c0a0a655a60674680bbe"), "user" "login": "irOn" "description": "Made of steel" "date": ISODate("2014-04-30T09:16:45.8...

You perform the following query; How many documents will be updated by the query?

Which of the following is a valid Replica Set configuration if you want: 1-Have 3 copies of everything 2- That RS3 is never primary 2- That RSI and RS2 can be primary? You had to s...

Addding the index {a:l} can potentially decrease the speed of which of the following operations? Check all that apply.

Consider the following example document from the sample collection. All documents in this collection have the same schema. Which of the following queries will replace this with the...

Which of the following are common uses of the mongo shell? Check all that apply

Which of the following is a valid insert statement in mongodb? Select all valid.

In order to ensure that you can maintain high availability in the face of server failure, you should implement which of the following?

Which features of relational database management systems were deliberately omitted in MongoDB and help us to obtain horizontal scalability? Check all that apply.

Suposse tou have the following collection with only 2 documents: If you run an aggregation query and use { $unwind: "$traits" } as the first stage, how many documents will be passe...

Which of the following is true of the mechanics of replication in MongoDB? Check all that apply.

Consider the following document: > db.c.find() { "_id" : 12, b : [ 3, 5, 7, 2, 1, -4, 3, 12 ] } Which of the following queries on the "c" collection will return only the first five...

Which of the following statements are true about the $match pipeline operator? Check all that apply.