Parallel scan in DynamoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a parallel scan in DynamoDB?

A parallel scan is a way to speed up reading all items in a DynamoDB table by dividing the table into segments and scanning each segment at the same time.

beginner

How does DynamoDB divide the table for a parallel scan?

DynamoDB divides the table into multiple segments, each segment is scanned independently and in parallel by separate workers or threads.

beginner

Why use parallel scan instead of a normal scan?

Parallel scan reduces the total time to scan a large table by using multiple workers to scan different parts at the same time, making it faster than scanning sequentially.

intermediate

What parameters do you need to specify for a parallel scan?

You need to specify the total number of segments and the segment number for each worker to scan its part of the table.

intermediate

Can parallel scan affect your DynamoDB table's performance?

Yes, because it uses multiple workers scanning at once, it can increase read capacity usage and may impact other operations if not managed carefully.

What does a parallel scan in DynamoDB do?

A Scans the table using multiple segments at the same time

B Scans the table one item at a time sequentially

C Deletes items in parallel

D Creates multiple tables for scanning

Parallel scan divides the table into segments and scans them simultaneously to speed up reading.

Which parameter is essential to specify for each worker in a parallel scan?

A Primary key value

B Table name

C Index name

D Segment number

Each worker must know which segment number it is scanning.

What is a potential downside of using parallel scan?

A It deletes data accidentally

B It can increase read capacity usage and affect performance

C It only works on small tables

D It requires creating new tables

Parallel scan uses more read capacity units because multiple segments are scanned at once.

How does DynamoDB split the work in a parallel scan?

A By creating multiple copies of the table

B By splitting the index keys

C By dividing the table into segments

D By partitioning the primary key values alphabetically

DynamoDB divides the table into segments for parallel scanning.

When is it best to use a parallel scan?

A When you need to scan a large table quickly

B When you want to update a single item

C When you want to create a new table

D When you want to delete a table

Parallel scan is useful to speed up scanning large tables.

Explain how parallel scan works in DynamoDB and why it can improve scan speed.

Think about splitting the work to do it faster.

What are the key parameters you must provide to perform a parallel scan in DynamoDB?

Each worker needs to know its part of the table.