MongoDB C100DBA Exam Dumps

Which of the following statements are true about the $match pipeline operator? Check all that apply.

• You should use it early as possible in the pipeline
• It can be used as many time as needed.
• It has a sintax similar to findQ commands.

Consider the following document:> db.c.find(){ '_id' : 12, b : [ 3, 5, 7, 2, 1, -4, 3, 12 ] }Which of the following queries on the 'c' collection will return only the first five elements of the array in the 'b'field? E.g.,Document you want returned by your query:{ '_id' : 12, 'b' : [ 3, 5, 7, 2, 1 ] >

• db.c.find( { > , { b : { $slice : [ 0 , 5 ] } } )
• db.c.find( { b : [ 0 , 5 ] > )
• db.c.find( { > , { b : { $substr[ 0 , 5 ] > > )
• db.c.find( { > , { b : [ 0, 1, 2, 3, 4, 5 ] > )
• db.c.find( { > , { b : [ 0 , 5 ] > )

What tool do you use if you want to extract a CSV from mongo?

Which of the following is true of the mechanics of replication in MongoDB? Check all that apply.

• Members of a replica set may replicate data from any other data-bearing member of the set by default
• Clients read from the nearest member of a replica ser by default
• Operations on the primary are recorded in a capped collection called the oplog

What tool do you use to see if you have a problem in the consumption of disk I / 0?