R4RIN – MCQs, Mock Tests | MongoDB MongoDB Mcq Question Set 8

MongoDB’s _______ is a database profiling system that can help identify inefficient queries and operations.

1. Reporter
2. Executer
3. Profiler
4. none of the mentioned

✅ Correct Answer: 3

With the _______ storage engine, MongoDB uses memory-mapped files to store data.

1. MMAPv2
2. MMAPv1
3. WiredTiger
4. All of the Mentioned

✅ Correct Answer: 2

Point out the correct statement.

1. Spikes in the number of available connections can also be the result of application or driver errors
2. For read-heavy applications, increase the size of your replica set and distribute read operations to secondary members
3. For read-heavy applications, deploy sharding and add one or more shards to a sharded cluster to distribute load among mongod instances
4. All of the Mentioned

✅ Correct Answer: 2

The memory usage statuses metrics of the _________ output can provide insight into MongoDB’s memory use.

1. globalstats
2. serverStatus
3. locks.deadlockCount
4. All of the mentioned

✅ Correct Answer: 2

Point out the wrong statement.

1. A single page fault completes slowly and is problematic
2. Increasing the amount of RAM accessible to MongoDB may help reduce the frequency of page faults
3. Page faults also can occur while accessing large data sets or scanning an entire collection
4. None of the mentioned

✅ Correct Answer: 1

You can inspect __________ to check the amount of mapped memory that mongod is using.

1. mem.mapped
2. memory.resident
3. mem.resident
4. All of the mentioned

✅ Correct Answer: 1

MongoDB reports its triggered page faults as the total number of page faults in ________ second.

1. 1
2. 100
3. 1000
4. none of the mentioned

✅ Correct Answer: 1

Which of the operator is used to access the query field of documents within system.profile?

1. $select
2. $retrieve
3. $query
4. None of the mentioned

✅ Correct Answer: 3

____ returns information on the query plan for aggregate function.

1. Reporter
2. db.collection.explain()
3. db.collection.explainplan()
4. None of the mentioned

✅ Correct Answer: 2

By default, db.collection.explain() runs in ___________ verbosity mode.

1. VerbosityMode
2. queryPlanner
3. executeStats
4. none of the mentioned

✅ Correct Answer: 2

____ does not provide query execution information for the rejected plans.

1. serverstats
2. queryPlanner
3. executionStats
4. All of the Mentioned

✅ Correct Answer: 3

Which of the following provides information on the MongoDB instance?

1. serverInfo
2. queryPlanner
3. executeStats
4. None of the mentioned

✅ Correct Answer: 1

_____ corresponds to the millis field returned by cursor.explain() in earlier versions of MongoDB.

1. executionMillis
2. executionTimeMillis
3. timemillis
4. All of the Mentioned

✅ Correct Answer: 2

For sharded collections, explain returns the __________ for each accessed shard.

1. clientInfo
2. serverInfo
3. serverplan
4. All of the Mentioned

✅ Correct Answer: 2

Point out the wrong statement.

1. If MongoDB can use an index scan to obtain the requested sort order, the result will not include a SORT stage
2. In previous versions of MongoDB, cursor.explain() returned the scanAndOrder field to specify whether MongoDB could use the index order to return sorted results
3. If MongoDB uses indexes for a $and expression, the result will include the AND stage with an inputStages array that details the replicata sets
4. none of the mentioned

✅ Correct Answer: 1

If the query planner selects a collection scan, the explain result includes a _________ stage.

1. COLLSCAN
2. TABLESCAN
3. ROWSCAN
4. All of the Mentioned

✅ Correct Answer: 1

Which of the following parameter specifies the verbosity mode for the explain output?

1. verbosity
2. verbose
3. queryPlanner
4. None of the mentioned

✅ Correct Answer: 2

In _____________ mode, MongoDB returns statistics describing the execution of the winning plan as well as statistics for the other candidate plans captured during plan selection.

1. somePlansExecution
2. allPlansExecution
3. rejPlansExecution
4. None of the mentioned

✅ Correct Answer: 2

If the query planner selects a _________ the explain result includes an IXSCAN stage.

1. Index
2. Replica Set
3. Document
4. None of the mentioned

✅ Correct Answer: 1

MongoDB stores additional instance-local metadata in the _______ database.

1. Master
2. Model
3. Local
4. All of the Mentioned

✅ Correct Answer: 3

Point out the correct statement.

1. You can limit the number of incoming connections using the maxConnections run-time option
2. mongos instances maintain a connection pool to each shard so that the mongos can reuse connections
3. You can use the limit command at the system prompt to check system limits
4. All of the Mentioned

✅ Correct Answer: 2

In replica sets, each ________ maintains a connection to all other members of the set.

1. serverInfo
2. mongod
3. mongos
4. None of the mentioned

✅ Correct Answer: 2

The ___________ collection stores the user’s authentication credentials as well as any roles assigned to the user.

1. admin.system.auth
2. admin.system.users
3. admin.system.usersauth
4. All of the mentioned

✅ Correct Answer: 2

Point out the wrong statement.

1. The “hard” ulimit refers to the maximum number of processes that a user can have active at any time
2. The “soft” ulimit refers to the minimum number of processes that a user can have active at any time
3. ulimit will modify both “hard” and “soft” values unless the -H or -S modifiers are specified when modifying limit values
4. none of the mentioned

✅ Correct Answer: 2

The <database>.system.indexes collection lists all the _________ in the database.

1. serverinfo
2. indexes
3. profiling
4. All of the Mentioned

✅ Correct Answer: 2

Which of the following The collection holds special JavaScript code for use in server side JavaScript?

1. <database>.system.jserver
2. <database>.system.jscript
3. <database>.system.js
4. None of the mentioned

✅ Correct Answer: 3

Which of the following can store JavaScript functions for reuse?

1. store.js
2. system.js
3. system.store.js
4. save.js

✅ Correct Answer: 2

___ is used to load all the scripts saved in the system.js collection for the current database.

1. db.loadServerScripts()
2. db.loadScripts()
3. db.loadServerScriptsjs()
4. None of the mentioned

✅ Correct Answer: 1

Which of the following information is captured by database profiler?

1. Read operations
2. Write operations
3. Cursor Operations
4. All of the Mentioned

✅ Correct Answer: 4

Point out the correct statement.

1. A limit() value of 0 (i.e. .limit(0)) is equivalent to setting no limit
2. The behavior of limit() is undefined for values less than -231 and greater than 231
3. You can use the ulimit command at the system prompt to check system limits
4. All of the Mentioned

✅ Correct Answer: 4

Which of the following collection is capped?

1. system.index
2. system.replica
3. system.profile
4. All of the Mentioned

✅ Correct Answer: 3

The ___________ provides information for various lock types and lock modes held during the operation.

1. admin.system.authlocks
2. system.profile.locks
3. admin.system.locks
4. All of the Mentioned

✅ Correct Answer: 2

Point out the wrong statement.

1. Beginning with version 3.0, MongoDB ships with the WiredTiger storage engine
2. Some global operations, typically short lived operations involving multiple databases, still require a global “instance-wide” lock
3. The MMAPv1 storage engine uses collection-level locking
4. None of the mentioned

✅ Correct Answer: 4

Which of the following keyword represents lock on the collection?

1. Database
2. Collection
3. Metadata
4. All of the Mentioned

✅ Correct Answer: 2

How many types of locking modes exist in MongoDB?

1. 1
2. 2
3. 3
4. More than 3

✅ Correct Answer: 4

Which of the following represents number of times the operation acquired the lock in the specified mode?

1. system.profile.locks.acquireCount
2. system.profile.locks.acquireWaitCount
3. system.profile.locks.Count
4. None of the mentioned

✅ Correct Answer: 1

____ can be used to limit the size of the result document for a query operation.

1. limit()
2. aggregate()
3. skip()
4. None of the mentioned

✅ Correct Answer: 1

Which of the following code is used for the successful exit of task?

1. 0
2. 1
3. 2
4. 3

✅ Correct Answer: 1

Point out the correct statement.

1. 2 is returned by mongod if there is a mismatch between hostnames specified on the command line and in the local.sources collection
2. When an index covers a query, MongoDB can both match the query conditions and return the results using only the index keys
3. Both 2 and 4 are returned by mongod if there is a mismatch between hostnames specified on the command line and in the local.sources collection
4. All of the Mentioned

✅ Correct Answer: 1

Instance exits cleanly are represented by ___ exit code.

1. 4
2. 1
3. 2
4. 3

✅ Correct Answer: 1

Which of the following code is returned by mongod if a moveChunk operation fails to confirm a commit?

1. 5
2. 6
3. 7
4. 3

✅ Correct Answer: 1

Point out the correct statement.

1. Exit code 10 is for abnormal exit
2. 4 is returned when the version of the database is different from the version supported by the mongod (or mongod.exe) instance
3. The server socket is on port 27017 by default
4. None of the mentioned

✅ Correct Answer: 2

Which of the following code represents exit cleanly following a large clock skew (32768 milliseconds) event?

1. 45
2. 20
3. 47
4. 100

✅ Correct Answer: 3

49 code is returned by mongod from _________ Service control Manager.

1. Linux
2. Windows
3. Ubuntu
4. All of the Mentioned

✅ Correct Answer: 1

Which of the following code is returned when a MongoDB application cannot open a file?

1. 45
2. 20
3. 47
4. 100

✅ Correct Answer: 1

Identify the message returned by MongoDB applications for Windows due to failures installing?

1. Message: ERROR: wsastartup failed <reason>
2. Message: NT Service Error
3. Message: wsastartup failed <reason>
4. none of the mentioned

✅ Correct Answer: 2

Which of the following document represents uncaught exception?

1. 45
2. 49
3. 47
4. 100

✅ Correct Answer: 4

Which of the following method is used for managing user?

1. db.createUser()
2. db.User()
3. db.superuser()
4. None of the mentioned

✅ Correct Answer: 1

Point out the correct statement.

1. Authentication is the process of verifying the identity of a client
2. When access control is enabled, MongoDB requires all clients to authenticate themselves first in order to determine the access for the client
3. Authentication and authorization are closely connected
4. All of the Mentioned

✅ Correct Answer: 4

MongoDB stores user information in the _________ collection.

1. system.allusers
2. system.users
3. system.superusers
4. system.usersnone

✅ Correct Answer: 2