None of the above

Object-oriented DBMS

Relational DBMS

Document-oriented DBMS

allPlansExecution

customExecutionStats

queryPlanner

executionStats

db.population.aggregate( [{ $group: { _id: { state: " $state " , city; " $city " },pop: { $sum: 1 > > > ] )

db.population.aggregate( [{ $group: { _id: { state: Estate " , city: " $city " },pop: { $pop: 1 } } }] )

db.population.aggregate( [{ $group: { _id: { state: Estate " , city: n$city " },pop: { $sum: " $pop " } } }] )

db.population.aggregate( [{ $group: { _id: { city: " $city " },pop: { $sum: " $pop " } } }] )Multi Document Transaction is not supported by MongoDB

2 MB document and 100 MB RAM

16 MB document and 100 MB RAM

No limit on document and 100 MB RAM

2 MB document and no limit on RAM

upsert command instead of update command

{update: true, insert: true} as the third parameter of update command

This has to be handled in application code (Node.js, PHP, JAVA, C#, etc.) and cannot be handled in mongo shell query

Specify {upsert : true } as the third parameter of update command

executionStats

queryPlanner

customExecutionStats

allPlansExecution

mapReduce

group

aggregate

All of the above

Sharding

Properly defined user roles

Replication

Put indexes on all of your documents

The proper storage engine

initializeUnorderedBulk

initializeUnorderedBulkOp

initializeBulk

initializeBulkOp

Transaction Management

ACID Transactions

Journaling

Relationships between Collections (Primary Key Foreign Key)