AWS Certified Data Analytics Specialty 2021 – Hands-On - DynamoDB RCU and WCU - Throughput

The video tutorial explains the two capacity modes in DynamoDB: provisioned and on-demand. It covers the details of provisioned mode, including read and write capacity units (RCU and WCU), auto-scaling, and burst capacity. The tutorial also delves into the calculations for WCU and RCU, highlighting the differences between strongly consistent and eventually consistent reads. It further explains how DynamoDB partitions data and the implications of hot partitions. Finally, the on-demand mode is discussed, emphasizing its flexibility and higher cost compared to provisioned mode.

What is the default mode for controlling table capacity in DynamoDB?

• Provisioned mode

• Burst mode

• On-demand mode

• Auto-scaling mode

In provisioned mode, what happens if you exceed the provisioned throughput?

• You are charged extra fees

• The system automatically scales up

• You can use burst capacity temporarily

• The system shuts down

What is the main benefit of using auto-scaling in provisioned mode?

• It reduces latency

• It automatically adjusts capacity to meet demand

• It lowers costs

• It increases data security

How many write capacity units (WCU) are needed for writing 10 items per second, each 2 KB in size?

• 5 WCU

• 20 WCU

• 10 WCU

• 15 WCU

What is the main difference between strongly consistent reads and eventually consistent reads?

• Eventually consistent reads require more RCU

• Strongly consistent reads ensure the latest data

• Eventually consistent reads are more expensive

• Strongly consistent reads are faster

How many read capacity units (RCU) are needed for 10 strongly consistent reads per second of 4 KB items?

• 10 RCU

• 15 RCU

• 20 RCU

• 5 RCU

What is a potential issue when a partition key is accessed too frequently?

• Data loss

• Automatic scaling

• Provision throughput exceeded exception

• Increased latency

In on-demand mode, what is a key advantage over provisioned mode?

• Lower cost

• Unlimited capacity

• Faster reads

• Automatic data replication

What is the cost implication of using on-demand mode compared to provisioned mode?

• It is cheaper

• It is 2.5 times more expensive

• It costs the same

• It is 50% more expensive

Which mode is more suitable for unpredictable application traffic?

• Burst mode

• Auto-scaling mode

• On-demand mode

• Provisioned mode