MongoDB Certified DBA Associate Exam (Based on MongoDB 4.4) - C100DBA Exam Practice Test

A. the primary may roll back the operations once it recovers

B. the secondary with the most current oplog will be elected primary

C. reads will be stale until the primary comes back up

D. the most current secondary will roll back the operations following the election

E. missing operations will need to be manually re-performed

A. 12 MB

B. 2 MB

C. There is no maximum size. It depends on the RAM.

D. 16 MB

A. db.stopServer( )

B. db.stopBalancer( )

C. sh.stopServer( )

D. sh.stopBalancer( )

A. $addToSet needs the fields to be already present while $push will work even if the field is not present

B. $addToSet adds the item to the field only if it does not exist already; while $push pushes the item to the field irrespective of whether it was present or not

C. There is no major difference between them. $addToSet is a deprecated version of $push.

D. $addToSet adds the item to the field only if the new item is of the same datatype

A. Write Concern

B. Indexing

C. Replication

D. Sharding

A. db.test.ensurelndex( { a : 1, c: 1, d: 1, b : 1})

B. db.test.ensurelndex( { a: 1, b :1, c:l, d:l})

C. CH db.test.ensurelndex( { a :1, c:l})

D. db.test.ensurelndex( { c:l, a: 1})