What does the following $slice query return using the following command? db.posts.find( {}, { comments: { $slice: [ -10, 5 ] } } )

• A.Returns 5 comments, beginning with the last 10 items
• B.Returns 10 comments, beginning with the first
• C.Returns 10 comments, beginning with the last
• D.Returns 5 comments, beginning with the first 10 items

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Using an arbiter allows one to easily ensure an odd number of voters in replica sets. Why is this important?

• A.To enable certain read preference settings
• B.To add greather redundancy
• C.To help in disaster recovery
• D.To protect agains network partitions
• E.For more efficient backup operations

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Which of the following collections stores authentication credentials in MongoDB?

• A.local.users
• B.users.users
• C.test.users
• D.system.users

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Consider a collection posts which has fields: Jd, post_text, post_author, post_timestamp, post_tags etc. Which of the following query retrieves ONLY the key named post_text from the first document retrieved?

• A.db.posts.finOne({},{_id:0, post_text:1})
• B.db.posts.finOne{},{post_text:l})
• C.db.posts.find({},{_id:Of post_text:1})
• D.db.posts.findOne({post_text: 1})

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Which mongodb tools allow us to work with our data in a human readable format?

• A.mongoexport
• B.mongoimport
• C.mongodump
• D.mongostat

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