81. Which command creates a MongoDB Atlas Search index?

• a) db.collection.createSearchIndex({...})
• b) db.createAtlasIndex()
• c) db.collection.makeSearchIndex()
• d) db.searchIndex()

82. What is the purpose of the $search aggregation stage?

• a) Performs full-text search using Atlas Search
• b) Searches across collections
• c) Implements regex search
• d) Validates search queries

83. Which operator performs graph traversal in MongoDB?

• a) $graphLookup
• b) $traverse
• c) $connect
• d) $path

84. What does the $collStats aggregation stage return?

• a) Collection storage and index statistics
• b) Collation settings
• c) Document count only
• d) Shard distribution

85. Which method safely shuts down a mongod instance?

• a) db.shutdownServer()
• b) db.stop()
• c) mongod --shutdown
• d) db.exit()

86. What is the purpose of the $planCacheStats operator?

• a) Displays query plan cache information
• b) Optimizes cache usage
• c) Clears stale plans
• d) Creates cached indexes

87. Which command creates a MongoDB view?

• a) db.createView("viewName", "source", [pipeline])
• b) db.view.create()
• c) db.makeView()
• d) db.collection.view()

88. What does the $indexStats aggregation stage return?

• a) Index usage statistics
• b) List of indexes
• c) Index creation commands
• d) Index storage size

89. Which operator implements Redact in aggregation?

• a) $redact
• b) $filter
• c) $mask
• d) $secure

90. What is the purpose of the $sample stage?

• a) Randomly selects documents
• b) Creates data samples
• c) Generates test data
• d) Divides collections

91. Which method returns MongoDB server status?

• a) db.serverStatus()
• b) db.status()
• c) mongod --status
• d) db.health()

92. What does the $mergeObjects operator do?

• a) Combines multiple documents
• b) Merges collections
• c) Joins sharded data
• d) Overwrites duplicate fields

93. Which command lists all MongoDB users?

• a) db.getUsers()
• b) show users
• c) db.users()
• d) db.listUsers()

94. What is the purpose of the $switch operator?

• a) Conditional branching in aggregations
• b) Changes database connections
• c) Swaps collection names
• d) Toggles indexes

95. Which operator validates BSON types?

• a) $type
• b) $bson
• c) $validate
• d) $checkType

96. What does the $dateFromString operator do?

• a) Converts string to date
• b) Formats date as string
• c) Validates date strings
• d) Parses timestamps

97. Which method exports MongoDB data to JSON?

• a) mongoexport
• b) mongodump
• c) db.export()
• d) saveAsJSON()

98. What is the purpose of the $concatArrays operator?

• a) Merges multiple arrays
• b) Concatenates strings
• c) Combines collections
• d) Joins sharded chunks

99. Which command enables MongoDB auditing?

• a) mongod --auditDestination
• b) db.enableAuditing()
• c) db.audit()
• d) audit.enable()

100. What does the $isoWeek operator return?

• a) ISO week number of the year (1-53)
• b) ISO timestamp
• c) ISO country code
• d) ISO formatted date