C100DBA Practice Exam Questions with Answers MongoDB Certified DBA Associate Exam (Based on MongoDB 4.4) Certification

$slice

$

All of the above

$ elemMatch

Create

update

insert

delete

mongotop

dbstats

mongostat

constats

allPlansExecution

customExecutionStats

queryPlanner

executionStats

test.users

local.users

system.users

users.users

db.posts.createIndex({^comments.$.author":-l});

db. posts.createIndex({^comments.author" :1});

db.posts.createIndex({^commerits.author";-!});

Replication

Indexing

Sharding

Journaling

backup mongodb deployment

audit mongodb deployment

performance tune mongodb deployment

replicate mongodb deployments

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

db.test.push({x:2,y:"apple"})

db.test.insert«"x":2, "y":"apple"})

db.test.insert({x:2,y:"apple"})

db.test.insert({x:2},{y:"apple"})

16 MB

12 MB

2 MB

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

Start the election process for primary

Vote for the first secondary so that it would become the next primary

Vote for itself and then call for election

Connect to primary to confirm its availability

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

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

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

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

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.