Scan pagination in DynamoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is scan pagination in DynamoDB?

Scan pagination is a way to retrieve large sets of data from a DynamoDB table in smaller chunks or pages, instead of all at once. This helps manage memory and network usage.

beginner

Which DynamoDB response attribute indicates there is more data to fetch during a scan?

The LastEvaluatedKey attribute in the scan response shows the last item processed. If it exists, it means there is more data to fetch in the next scan call.

intermediate

How do you continue scanning after receiving a LastEvaluatedKey?

Use the ExclusiveStartKey parameter in the next scan request and set it to the LastEvaluatedKey value from the previous response to continue from where you left off.

beginner

Why should you avoid scanning an entire DynamoDB table at once?

Scanning the entire table at once can cause high latency, consume a lot of read capacity, and may lead to timeouts or throttling. Pagination helps by breaking the scan into smaller, manageable parts.

beginner

What is a practical real-life example of using scan pagination?

Imagine you have a large list of customer orders in DynamoDB. Instead of loading all orders at once, you fetch 100 orders at a time using scan pagination. This keeps your app fast and responsive.

What does the LastEvaluatedKey in a DynamoDB scan response mean?

A The table is empty

B The scan is complete

C There is more data to scan

D An error occurred

If LastEvaluatedKey is present, it means the scan stopped before reading all items and you can continue scanning from this key.

Which parameter do you use to continue a scan from where it left off?

A StartKey

B ExclusiveStartKey

C LastEvaluatedKey

D NextPageKey

You pass the LastEvaluatedKey from the previous response as the ExclusiveStartKey in the next scan request.

Why is scan pagination important in DynamoDB?

A To reduce memory and network load

B To speed up writes

C To encrypt data

D To create indexes

Pagination breaks large scans into smaller parts, reducing memory and network usage.

What happens if you do not use pagination on a large scan?

A Scan may timeout or be throttled

B Scan will be faster

C Data will be deleted

D Table will be locked

Scanning large tables without pagination can cause timeouts or throttling due to resource limits.

In scan pagination, what is the typical size of each page of results?

A Exactly 1000 items

B The entire table

C Only one item

D A small chunk like 100 items

Pages usually contain a manageable number of items, like 100, to keep performance smooth.

Explain how scan pagination works in DynamoDB and why it is useful.

Think about how you would read a big book in small parts instead of all at once.

Describe the steps to implement scan pagination in a DynamoDB application.

Imagine flipping pages in a book, one after another.