Which of the following commands will find all the posts that have been tagged as tutorial?

Regarding data modeling in MongoDB, which of the following is correct ?

Choose the best description of the output for the query below var weekAgo = Date.now() - (1000*60*60*24*7); db.visits_calc.group( { key:{date:true}, cond:{date:{$gt:weekAgo}}, reduce:function(obj, out) {out.day += obj.total}, initial:{day:0} });

What will be the output of two command in MongoDB: db.mycol.insert({'_id':1}) db.mycol.insert({'_id':1})

Which expression can not be used with aggregation?

Best statement that describes: 'why aggregation queries outperform mapreduce for small datasets'.

Which is the correct order in pipelining in mongo aggregation?

How many members a replica set can have?

Which method will shut down replica set?

how indexing improve query response time

For the query below db.collection.find( { x: 5 } ).sort( { z: 1} ) Choose the best index to support the query