Top MongoDB C100DBA Courses Online - Updated [Dec-2021]
C100DBA Practice Dumps - Verified By DumpsTorrent Updated 123 Questions
NEW QUESTION 72
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. <replicasetid>.oplog.rs
- B. oplog.rs
- C. <database>..oplog.rs
- D. local.oplog.rs
Answer: D
NEW QUESTION 73
The difference between $push and $addToSet is:
- A. $addToSet needs the fields to be already present while $push will work even if the field is not present
- B. $addToSet adds the item to the field only if it does not exist already; while $push pushes the item to the field irrespective of whether it was present or not
- C. There is no major difference between them. $addToSet is a deprecated version of $push.
- D. $addToSet adds the item to the field only if the new item is of the same datatype
Answer: B
NEW QUESTION 74
Which of the following operator can be used to limit the number of documents in an array field of a document after an update is performed?
- A. $push along with $each, $sort and $slice
- B. $removeFromSet
- C. $arrayLimit
- D. None of the above
Answer: A
NEW QUESTION 75
What is the use of mongodump and mongorestore tools?
- A. audit mongodb deployment
- B. replicate mongodb deployments
- C. backup mongodb deployment
- D. performance tune mongodb deployment
Answer: C
NEW QUESTION 76
Which are the ONLY ways to project portions of an array?
- A. $slice
- B. $ elemMatch
- C. All of the above
- D. $
Answer: C
NEW QUESTION 77
Which of the following does MongoDB use to provide High Scalability?
- A. Replication
- B. Indexing
- C. Write Concern
- D. Sharding
Answer: D
NEW QUESTION 78
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 ] >
- A. db.c.find( { > , { b : { $substr[ 0 , 5 ] > > )
- B. db.c.find( { > , { b : { $slice : [ 0 , 5 ] } } )
- C. db.c.find( { b : [ 0 , 5 ] > )
- D. db.c.find( { > , { b : [ 0 , 5 ] > )
- E. db.c.find( { > , { b : [ 0, 1, 2, 3, 4, 5 ] > )
Answer: B
NEW QUESTION 79
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 query return? Check all that apply.
db.sayings.find( { $text : { $search : "fact find" } } )
- A. { _id : 3, quote : "Nobody will ever catch me." }
- B. { _id : 2, quote : "Find out if that fact is correct." }
- C. { _id : 1, quote : "That's a fact, Jack." }
Answer: B,C
NEW QUESTION 80
Given a collection posts as shown below having a document array comments, which of the following command will create an index on the comment author descending?
- A. db. posts.createIndex({^comments.author" :1});
- B. db.posts.createIndex({^commerits.author";-!});
- C. db.posts.createIndex({^comments.$.author":-l});
Answer: B
NEW QUESTION 81
In a replica set, a_________number of members ensures that the replica set is always able to select a primary.
- A. Depends on the application architecture
- B. 0
- C. Odd
- D. Even
Answer: C
NEW QUESTION 82
Consider the following example document:
{
"_id": Objectld("5360c0a0a655a60674680bbe"),
"user"
"login": "irOn"
"description": "Made of steel"
"date": ISODate("2014-04-30T09:16:45.836Z"),
}
>
and index creation command:
db.users.createlndex( { "user.login": 1, "user.date": -1 }, "mylndex" ) When performing the following query:
db.users.find( { "user.login": /Air.*/ },
{ "user":1, "_id":0 > ).sort( { "user.date":1 > )
which of the following statements correctly describe how MongoDB will handle the query? Check all that apply.
- A. As an optimized sort query (scanAndOrder = false) using "mylndex" because we are sorting on an indexed field
- B. As a covered query using "mylndex" because we are filtering out "_id" and only returning "user.login"
- C. None of the above
- D. MongoDB will need to do a table/collection scan to find matching documents
- E. As an indexed query using "mylndex" because field "user.login" is indexed
Answer: E
NEW QUESTION 83
Which is the default mode in which the explain() command runs?
- A. queryPlanner
- B. allPlansExecution
- C. executionStats
- D. customExecutionStats
Answer: A
NEW QUESTION 84
By default, the MongoDB cursor in mongo shell is configured to return how many documents? To get the next set of documents, which command is used?
- A. 20, it
- B. 200, more
- C. 50, it
- D. No limit, none
Answer: A
NEW QUESTION 85
What is the replication factor for a replicated cluster with 1 primary, 3 secondaries with one of them hidden.
The set also has an arbiter?
- A. 0
- B. None of the above
- C. 1
- D. 2
Answer: A
NEW QUESTION 86
In what format does mongodump creates backup files?
- A. JSON
- B. XML
- C. BSON
- D. SOAP
Answer: C
NEW QUESTION 87
In a sharded replicas set environment with multiple mongos servers, which of the following would decide the mongos failover?
- A. mongod
- B. mongo shell
- C. individual language drivers
- D. mongos
Answer: C
NEW QUESTION 88
What is the output of the following program?
- A. 1s
- B. 100 s
- C. 100 ms
- D. 60 s
Answer: D
NEW QUESTION 89
Mongodb does provide high availability via which option?
- A. Replication
- B. Indexing
- C. Journaling
- D. Sharding
Answer: A
NEW QUESTION 90
Which of the following is supported by MongoDB?
- A. ACID Transactions
- B. Relationships between Collections (Primary Key Foreign Key)
- C. Journaling
- D. Transaction Management
Answer: C
NEW QUESTION 91
In a sharded cluster, from which node does one stop the balancer process before initiating backup?
- A. Any node
- B. replicaset primary node
- C. mongos node
- D. config server node
Answer: C
NEW QUESTION 92
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