Backup can also create snapshots of _________ that are run as single-member replica sets.
documents
standalones
backups
none of the mentioned
Select the wrong statement :
Query selectivity refers to how well the query predicate excludes or filters out documents in a collection
Query selectivity can determine whether or not queries can use indexes effectively or even use indexes at all
More selective queries match a larger percentage of documents
All of the mentioned
Select the correct statement :
In MongoDB, clients cannot see the results of writes before they are made durable
Users may configure read preference on a per-connection basis to prefer that the read operations return results from the secondary members
Clients cannot read data which may be subsequently rolled back
None of the mentioned
$multiply __________ numbers to return the result.
multiplies
divides
comapres
all of the mentioned
_____________ is used to initiate relica member set.
rs.rep()
rs.init()
rs.initiate()
A query may include a ___________ that specifies the fields from the matching documents to return.
selection
projection
union
Map-reduce uses custom __________ functions to perform the map and reduce operations.
Java
Javascript
JSON
MongoDB stores all documents in :
tables
collections
rows
Point out the correct statement :
The amount of oplog to keep per backup is configurable and affects the time window available for checkpoint and point-in-time restores
To get a consistent snapshot of a sharded system, you must enable the balancer
Backups produced by copying the underlying data do support point in time recovery
MongoDB written in ?
C
C++
MongoDB provides a ________ index type that supports searching for string content in a collection.
string
text
char
MongoDB scales horizontally using _________ for load balancing purpose.
Replication
Partitioning
Sharding
________ subtracts two dates to return the difference in milliseconds
$rem
$mod
$div
$subtract
String expressions, with the exception of ________ only have a well-defined behavior for strings of ASCII characters.
$setcon
$concatenation
$concat
In the mongo shell, you can access the creation time of the ObjectId, using the ______ method..
getTime()
getTimestamp()
Timestamp()
Select the correct statement:
High query rates can exhaust the CPU capacity of the server
Database systems with small data sets and high throughput applications can challenge the capacity of a single server
Smaller data sets exceed the storage capacity of a single machine
_______ may block reads, including those necessary to verify authentication.
db.lockall()
db.fsyncLock()
db,lockreads()
MongoDB supports the execution of JavaScript code for certain server-side operations like:
where
group
mapreduce
Which of the following flag can be set by mongo shell
Timeout
noTimeout
Time
The aggregation pipeline can use ___________ to improve its performance during some of its stages.
indexes
OptmData
functions
_______ is /srv/mongodb, which specifies where MongoDB will store its data files
dbPath
dbPathSts
db.Op
Which of the following will display complete list of available cursor flags ?
cursor.Option()
cursor.addOption()
cursor.addOptions()
Secondary indexes allow applications to store a view of a portion of the collection in an efficient data structure
MongoDB has full support for secondary indexes
Most indexes store an ordered representation of all values of a field or a group of fields
MongoDB applies the _________ phase, which collects and condenses the aggregated data.
map
reduce
mapper
Which of the following operator is not very selective ?
$nine
$nin
$ain
MongoDB supports the creation of user-defined ascending/descending indexes on a ______ field of a document.
Single
Non Unique
Compound
____________ are operations that process data records and return computed results.
ReplicaAgg
SumCalculation
Aggregations
Point out the wrong statement :
Authentication does not require an authentication mechanism
To enable authentication on a sharded cluster, you must enable authentication individually on each component of the cluster
The content of the key file must be the same on all cluster members
Documents enter a multi-stage __________ that transforms the documents into an aggregated result.
pipeline
pipelineView
pipelineUser
MongoDB process collection of documents using _________ operations.
Hbase
Hive
Map-reduce