Database - Mongodb - Mongodb Question And Answers

MongoDB written in ?

A.  Javascript

B.  C

C.  C++

D.  All of the mentioned

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Select the correct statement :

A.  MongoDB is classified as a NoSQL database

B.  MongoDB favours XML format more than JSON

C.  MongoDB is column oriented database store

D.  All of the mentioned

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In which format MongoDb store the data.

A.  SQL

B.  XML

C.  BSON

D.  All of the mentioned

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Select the wrong statement :

A.  Secondary indices is not available in MongoDB

B.  MongoDB supports search by field, range queries, regular expression searches

C.  MongoDB can store the business subject in the minimal number of documents

D.  All of the mentioned

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Select the correct statement:

A.  High query rates can exhaust the CPU capacity of the server

B.  Database systems with small data sets and high throughput applications can challenge the capacity of a single server

C.  Smaller data sets exceed the storage capacity of a single machine

D.  All of the mentioned

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How many types of sharding exist in MongoDB ?

A.  1

B.  2

C.  3

D.  All of the mentioned

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_______ scaling adds more CPU and storage resources to increase capacity.

A.  Horizontal

B.  Vertical

C.  Partition

D.  All of the mentioned

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Select the wrong statement :

A.  Scaling by adding capacity do not have limitations.

B.  cloud-based providers may only allow users to provision smaller instances

C.  There is a practical maximum capability for vertical scaling

D.  All of the mentioned

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_______ divides the data set and distributes the data over multiple servers, or shards.

A.  Vertical

B.  Sharding

C.  Partition

D.  All of the mentioned

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To provide high availability and data consistency, in a production sharded cluster, each shard is a :

A.  replica set

B.  cluster

C.  partition

D.  all of the mentioned

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_______ may block reads, including those necessary to verify authentication.

A.  db.lockall()

B.  db.fsyncLock()

C.  db,lockreads()

D.  none of the mentioned

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Select the correct statement :

A.  In MongoDB, clients cannot see the results of writes before they are made durable

B.  Users may configure read preference on a per-connection basis to prefer that the read operations return results from the secondary members

C.  Clients cannot read data which may be subsequently rolled back

D.  None of the mentioned

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Delayed members are a ________ or a running “historical” snapshot of the data set

A.  “rolling backup”

B.  “roll backup”

C.  “rolling commit”

D.  none of the mentioned

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In sharded clusters, delayed members have limited utility when the __________ is enabled.

A.  Balancer

B.  Collector

C.  Emitter

D.  None of the mentioned

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MongoDB indexes use a _______ data structure.

A.  Hash

B.  Map

C.  B-tree

D.  All of the mentioned

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Select the correct statement :

A.  If an appropriate index exists for a query, MongoDB cannot use the index to limit the number of documents it must inspect

B.  Indexes support the efficient execution of queries in MongoDB

C.  The index stores the location of a specific field or set of fields, ordered by the value of the field

D.  None of the mentioned

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MongoDB supports the creation of user-defined ascending/descending indexes on a ______ field of a document.

A.  Single

B.  Non Unique

C.  Compound

D.  None of the mentioned

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The ______ index is unique and prevents clients from inserting two documents with the same value for the _id field.

A.  _id

B.  $default

C.  _def

D.  None of the mentioned

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Select the wrong statement :

A.  MongoDB can return sorted results by using the ordering in the index

B.  MongoDB defines indexes at the collection level and supports indexes on any field or sub-field of the documents in a MongoDB collection

C.  Fundamentally, indexes in MongoDB is different to indexes in other database systems

D.  None of the mentioned

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MongoDB also supports user-defined indexes on multiple fields called :

A.  compound

B.  composite

C.  candidate

D.  none of the mentioned

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MongoDB uses ______ indexes to index the content stored in arrays.

A.  singlekey

B.  multikey

C.  compkey

D.  none of the mentioned

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MongoDB provides a ________ index type that supports searching for string content in a collection.

A.  string

B.  text

C.  char

D.  none of the mentioned

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Indexes are typically available in ______ or located sequentially on disk.

A.  RAM

B.  ROM

C.  CMOS

D.  None of the mentioned

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Select the wrong statement :

A.  Query selectivity refers to how well the query predicate excludes or filters out documents in a collection

B.  Query selectivity can determine whether or not queries can use indexes effectively or even use indexes at all

C.  More selective queries match a larger percentage of documents

D.  All of the mentioned

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___________ is used to determine whether a query is a covered query .

A.  explainstats()

B.  explain()

C.  explainall()

D.  all of the mentioned

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The ________ message is used to update a document in a collection.

A.  UPDATE

B.  OP_UPDATE

C.  OP_UPDATES

D.  All of the mentioned

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The update() method uses the _______ command, which uses the default write concern.

A.  find

B.  read

C.  update

D.  modify

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An ________ query plan has returned a threshold number of matching results

A.  execution

B.  unordered

C.  ordered

D.  none of the mentioned

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A query _______ consists of a combination of query, sort, and projection specifications.

A.  plan

B.  shape

C.  stats

D.  all of the mentioned

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A query may include a ___________ that specifies the fields from the matching documents to return.

A.  selection

B.  projection

C.  union

D.  none of the mentioned

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