Identifying access patterns first in DynamoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the primary key attribute name in a DynamoDB table creation.

DynamoDB

KeySchema: [{ AttributeName: [1], KeyType: 'HASH' }]

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AUserId

BTimestamp

CEmail

DStatus

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a non-unique attribute like 'Status' as primary key.

The primary key attribute name is usually a unique identifier like 'UserId'.

2fill in blank

medium

Complete the code to define a Global Secondary Index (GSI) partition key.

DynamoDB

GlobalSecondaryIndexes: [{ IndexName: 'StatusIndex', KeySchema: [{ AttributeName: [1], KeyType: 'HASH' }] }]

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

AUserId

BEmail

CTimestamp

DStatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using the primary key attribute 'UserId' as GSI key.

The GSI partition key is often an attribute like 'Status' to query items by their status.

3fill in blank

hard

Fix the error in the query to get an item by primary key.

DynamoDB

const params = { TableName: 'Users', Key: { [1]: '12345' } };

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AStatus

BEmail

CUserId

DTimestamp

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-primary key attribute in the Key object.

The Key must use the primary key attribute name, which is 'UserId' here.

4fill in blank

hard

Fill both blanks to create a query using a GSI to find items by status and sort by timestamp.

DynamoDB

const params = { TableName: 'Orders', IndexName: 'StatusIndex', KeyConditionExpression: '[1] = :statusVal AND [2] > :timeVal', ExpressionAttributeValues: { ':statusVal': 'shipped', ':timeVal': 1609459200 } };

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AStatus

BUserId

CTimestamp

DOrderId

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping partition and sort key names.

The query uses 'Status' as the partition key and 'Timestamp' as the sort key in the GSI.

5fill in blank

hard

Fill all three blanks to create a DynamoDB update expression that sets a new status and increments a counter.

DynamoDB

const params = { TableName: 'Tasks', Key: { TaskId: 'task123' }, UpdateExpression: 'SET [1] = :newStatus, [2] = [3] + :inc', ExpressionAttributeValues: { ':newStatus': 'completed', ':inc': 1 } };

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AStatus

BCounter

CCount

DProgress

Attempts:

3 left

💡 Hint

Common Mistakes

Using different attribute names for increment operation.

The update expression sets the 'Status' attribute and increments the 'Count' attribute by 1.