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Lesson 22 / 23

MongoDB Atlas at a Glance

Run MongoDB in the cloud with Atlas, get a connection string and practise on the free M0 tier.

A managed database

Atlas is MongoDB's fully-managed cloud service — it handles provisioning, backups, monitoring and scaling for you.

Connecting to an Atlas cluster

Atlas gives you a connection string to use from mongosh or your app's driver.

mongosh "mongodb+srv://cluster0.abcde.mongodb.net/myDb" --username ada

Free tier to learn on

The M0 free-tier cluster is enough to practice everything in this course without spending anything.

Final quiz 1 of 8

Final quiz

Quick check: What format does MongoDB use to store documents?

  • XML
  • CSV
  • BSON
  • YAML
Answer

BSON — BSON extends JSON with types such as Date and ObjectId.

Final quiz 2 of 8

Final quiz

Quick check: Which method adds one document?

  • addDoc
  • push
  • create
  • insertOne
Answer

insertOne — insertOne creates the collection if needed.

Final quiz 3 of 8

Final quiz

Quick check: Which operator appends to an array field?

  • $push
  • $set
  • $inc
  • $unset
Answer

$push — $push adds a value to an array.

Final quiz 4 of 8

Final quiz

Quick check: What does an IXSCAN in explain() show?

  • A full collection scan
  • An index was used
  • A syntax error
  • An empty result
Answer

An index was used — COLLSCAN is the slow full scan.

Final quiz 5 of 8

Final quiz

Quick check: When should you embed related data?

  • When it grows without limit
  • When it is shared by many parents
  • When it is read together and stays small
  • Never
Answer

When it is read together and stays small — Embedding gives one fast read for bounded data.

Final quiz 6 of 8

Final quiz

Quick check: What does the $group stage do?

  • Filters documents
  • Deletes documents
  • Renames fields
  • Aggregates documents by a key
Answer

Aggregates documents by a key — $group computes sums, counts and averages per key.

Final quiz 7 of 8

Final quiz

Quick check: What does a replica set provide?

  • High availability through copies and failover
  • More storage per node
  • Schema validation
  • Faster inserts
Answer

High availability through copies and failover — A secondary is promoted if the primary fails.

Final quiz 8 of 8

Final quiz

Quick check: Which problem does sharding mainly solve?

  • Password resets
  • Scaling storage and throughput
  • Date formatting
  • Backups only
Answer

Scaling storage and throughput — Shards split data across servers by shard key.