Transaction isolation in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a transaction in MongoDB.

MongoDB

const session = client.startSession();
session.[1]();

Drag options to blanks, or click blank then click option'

AstartTransaction

BinitTransaction

CbeginTransaction

DopenTransaction

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'beginTransaction' instead of 'startTransaction'.

Trying to call 'openTransaction' which does not exist.

In MongoDB, the correct method to start a transaction on a session is startTransaction().

2fill in blank

medium

Complete the code to commit a transaction in MongoDB.

MongoDB

await session.[1]();

Drag options to blanks, or click blank then click option'

AfinalizeTransaction

BcommitTransaction

CendTransaction

Dcommit

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'commit' which is not a method on the session.

Using 'endTransaction' which does not exist.

The correct method to commit a transaction in MongoDB is commitTransaction().

3fill in blank

hard

Fix the error in the code to abort a transaction in MongoDB.

MongoDB

await session.[1]();

Drag options to blanks, or click blank then click option'

AabortTransaction

Babort

CrollbackTransaction

DcancelTransaction

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'rollbackTransaction' which is not a MongoDB method.

Using 'abort' without 'Transaction'.

The correct method to abort a transaction in MongoDB is abortTransaction().

4fill in blank

hard

Fill both blanks to set transaction options for read concern and write concern.

MongoDB

const transactionOptions = {
  readConcern: { level: '[1]' },
  writeConcern: { w: '[2]' }
};

Drag options to blanks, or click blank then click option'

Asnapshot

Bmajority

Clocal

Dlinearizable

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'local' for readConcern in transactions which is weaker.

Using 'linearizable' which is not a valid readConcern level.

For transaction isolation, readConcern is often set to snapshot and writeConcern to majority to ensure strong consistency.

5fill in blank

hard

Fill all three blanks to run a transaction with a callback function.

MongoDB

await session.withTransaction(async () => {
  await collection.[1](doc, { session });
  await collection.[2]({ _id: id }, { session });
}, { readConcern: { level: '[3]' } });

Drag options to blanks, or click blank then click option'

AinsertOne

BdeleteOne

Csnapshot

DupdateOne

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'updateOne' instead of 'deleteOne' for deletion.

Using 'local' instead of 'snapshot' for readConcern.

Inside a transaction callback, you can perform operations like insertOne and deleteOne. The transaction's read concern is set to snapshot for isolation.