Change stream events (insert, update, delete) in MongoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a change stream in MongoDB?

A change stream lets you watch real-time changes (like insert, update, delete) happening in your MongoDB database collections.

beginner

Which change stream event is triggered when a new document is added?

The insert event is triggered when a new document is added to a collection.

beginner

What does the update event in a change stream represent?

The update event means an existing document was changed, like modifying one or more fields.

beginner

What happens during a delete event in a MongoDB change stream?

A delete event means a document was removed from the collection.

intermediate

How can you use change streams to keep your app data updated?

You listen to change stream events (insert, update, delete) and update your app's data or UI instantly when changes happen in the database.

Which change stream event occurs when a document is removed?

A insert

B delete

C update

D replace

The delete event is triggered when a document is removed from the collection.

What type of change stream event is triggered when a document's field value changes?

A drop

B insert

C delete

D update

The update event happens when an existing document is modified.

Which event would you listen to if you want to know when new data is added?

A insert

B invalidate

C delete

D update

The insert event is for new documents added to the collection.

Can change streams detect multiple types of events?

A No, only update

B No, only insert

C Yes, insert, update, delete, and more

D No, only delete

Change streams can detect insert, update, delete, replace, and other events.

What is a practical use of MongoDB change streams?

A To watch real-time data changes and update apps instantly

B To backup data manually

C To create indexes

D To delete collections

Change streams help apps react instantly to data changes by watching events like insert, update, and delete.

Explain what insert, update, and delete events mean in MongoDB change streams.

Think about what happens to documents in a collection when these events occur.

Describe how change streams can help keep an application’s data in sync with the database.

Imagine your app needs to show live data changes without refreshing.