MongoDB Aggregation & Indexing Quiz (original) (raw)

What is the purpose of the MongoDB aggregation framework?

• To modify existing documents
• To perform complex data transformations and analysis
• To store multiple collections in a database
• To enforce schema validation

Which aggregation stage is used to group documents based on a specific field?

What does the $lookup stage do in MongoDB aggregation?

• Retrieves documents from another collection
• Sorts documents in ascending or descending order
• Filters documents based on conditions
• Removes duplicate documents from the result

Which aggregation stage is used to filter documents before processing?

What is the primary purpose of the $out stage in MongoDB aggregation?

• Outputs results as a new collection
• Displays results in a formatted way
• Exports aggregation results to a JSON file
• Removes specific fields from the output

What is the main advantage of using indexes in MongoDB?

• Improve query performance
• Prevent duplicate records

How do you create an index on a single field in MongoDB?

• db.collection.addIndex({ field: 1 })
• db.collection.createIndex({ field: 1 })
• db.collection.index({ field: 1 })
• db.collection.ensureIndex({ field: 1 })

Which type of index is used to search text in MongoDB?

What happens when you drop an index in MongoDB?

• The index is permanently removed
• The collection is deleted
• MongoDB rolls back to an older state
• Queries become more efficient

What is the purpose of a compound index in MongoDB?

• To store multiple indexes in one collection
• To allow indexing on multiple fields
• To create a separate collection for indexed fields
• To convert numeric fields into indexed strings

There are 10 questions to complete.

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