MongoDB C100DBA Quiz 1 Topic 1 Questions 1-5

Question: 1

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 see the different configurations, RS3 could be hidden or priority 0 (But not a referee because we need

3 replicas), while RSI and RS2 could NOT have priority 0 or be hidden or anything like that

In a 4-member RS RSO , RSI, RS2 and RS3 + Referee, RSO (primary) falls after some write operations that have

replicated RSI and RS2 (but NOT RS3), who can get up as the new primary?

The configuration comes and in it we see that RS2 has a hidden: true (or a priority: 0, (I don't remember)

AORS1

BORS2

CORS3

DO arbiter

ERSO

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Question: 2

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( { '$or' : [ { 'a' : { '$in' : [ 3, 10] > }, { 'b' : { '$lt' : 2 > > ] > )

A{''_ _id' : 3, 'a' : 4, 'c' : 0, 'b' : 14}

B{''_ Jd' : 7, 'a' : 8, 'c' : 1, 'b' : 7}

C{'. Jd' : 6, 'a' : 1, 'c' : 1, 'b' : 5}

D{ ''\ Jd' : 9, 'a' : 17, 'c' : 1, 'b' : 1}

E{ \ Jd' : 10,'a' : 3, 'c' : 1, 'b' : 1}

F{'. Jd' : : 2, 'a' : 2, 'c' : : 0, 'b' : 1}

G{'. Jd' : : 4, 'a' : 5, 'c' : : 0, 'b' : 17}

H{'. Jd' : : 1, 'a' : 0, 'c' : : 0, 'b' : 2}

I{'. Jd' : : 5, 'a' : 3, 'c' : : 0, 'b' : 12}

J{'. Jd' : : 8, 'a' : 11, 'c' : 1, 'b' : 0}

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Question: 3

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

A{ '-id' : Objectld('580a42b5dfblb5al7427d302'), 'nombre' : 'ruben', 'apellido' : 'gomez', 'aficion' : v u 'flipar' }

B{ '_id' : Objectld('580a42acdfblb5al7427d301'), 'nombre' : 'Luis', 'apellido' : 'gomez', 'aficion' : u 'flipar' }

C{ '_id' : Objectld('580a42acdfblb5al7427d301'), 'nombre' : 'ruben', 'apellido' : 'Pablo' , 'aficion' : u 'flipar'}

D{ '_id' : Objectld('580a42acdfblb5al7427d301'), 'nombre' : 'ruben', 'apellido' : 'gomez' >

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Question: 4

What is the output of following two commands in MongoDB: db. posts. insert({n_id':l}) db.posts.insert({'_id':l})

ATwo documents will be inserted with _id as 1

BMongoDB will automatically increment the _id of the second document as 2

CThis will throw a duplicate key error

DIt will insert two documents and throw a warning to the user

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Question: 5

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 elements of the array in the 'b'

field? E.g.,

Document you want returned by your query:

{ '_id' : 12, 'b' : [ 3, 5, 7, 2, 1 ] >

Adb.c.find( { > , { b : { $slice : [ 0 , 5 ] } } )

Bdb.c.find( { b : [ 0 , 5 ] > )

Cdb.c.find( { > , { b : { $substr[ 0 , 5 ] > > )

Ddb.c.find( { > , { b : [ 0, 1, 2, 3, 4, 5 ] > )

Edb.c.find( { > , { b : [ 0 , 5 ] > )

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MongoDB C100DBA Quiz:1 Topic:1 Questions:1-5