Table capacity modes (on-demand vs provisioned) in DynamoDB - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Difference in billing between on-demand and provisioned capacity modes

Which statement correctly describes how billing works for DynamoDB tables using on-demand capacity mode compared to provisioned capacity mode?

A On-demand charges based on the number of read/write requests, while provisioned charges a fixed rate regardless of usage.

B Provisioned charges based on the number of read/write requests, while on-demand charges a fixed monthly fee.

C On-demand charges a fixed monthly fee, and provisioned charges based on storage size only.

D Provisioned charges based on storage size only, and on-demand charges based on the number of read/write requests.

💡 Hint

Think about how you pay for what you use versus paying for reserved capacity.

On-demand capacity mode charges you only for the read and write requests your application makes. Provisioned capacity mode requires you to specify the number of reads and writes you expect, and you pay for that capacity whether you use it or not.

❓ query_result

intermediate

Result of switching capacity mode on a DynamoDB table

What happens to the table's capacity settings immediately after switching from provisioned to on-demand mode?

A The provisioned capacity units remain active and are billed alongside on-demand usage.

B The provisioned read and write capacity units are ignored and replaced by on-demand billing.

C The table is deleted and recreated with on-demand mode, losing all data.

D The table continues to use provisioned capacity until manually updated.

💡 Hint

Consider how capacity modes affect billing and usage immediately after switching.

When you switch to on-demand mode, the table no longer uses provisioned capacity units. Instead, it bills based on actual read/write requests.

❓ optimization

advanced

Choosing capacity mode for unpredictable traffic

You expect your DynamoDB table to have highly variable and unpredictable traffic spikes. Which capacity mode is best to minimize cost and avoid throttling?

A Provisioned mode with fixed capacity set to the highest expected traffic.

B Provisioned mode with auto-scaling enabled to adjust capacity automatically.

C On-demand mode to pay only for the requests made without capacity planning.

D Provisioned mode with manual capacity adjustments during spikes.

💡 Hint

Think about which mode handles unpredictable traffic without manual intervention.

On-demand mode automatically handles traffic spikes by charging per request, avoiding throttling without needing capacity planning.

🔧 Debug

advanced

Identifying cause of throttling in provisioned mode

A DynamoDB table using provisioned capacity mode is experiencing throttling errors despite having capacity units set higher than average usage. What is the most likely cause?

A Traffic spikes exceeded provisioned capacity units temporarily causing throttling.

B On-demand mode was accidentally enabled causing billing conflicts.

C The table's storage size exceeded the provisioned capacity units.

D Provisioned capacity units automatically scale down causing throttling.

💡 Hint

Think about how provisioned capacity handles sudden traffic spikes.

Provisioned capacity does not instantly scale for spikes, so temporary traffic bursts above provisioned units cause throttling.

🧠 Conceptual

expert

Impact of capacity mode on global secondary indexes (GSIs)

How does the choice between on-demand and provisioned capacity modes affect the billing and capacity management of Global Secondary Indexes (GSIs) in DynamoDB?

A GSIs do not consume capacity units and are free to use.

B GSIs always use provisioned capacity mode regardless of the table's mode.

C GSIs always use on-demand capacity mode regardless of the table's mode.

D GSIs inherit the table's capacity mode; on-demand tables have on-demand GSIs billed per request, provisioned tables require separate capacity units for GSIs.

💡 Hint

Consider how GSIs are billed in relation to the main table's capacity mode.

GSIs follow the capacity mode of their parent table. If the table is on-demand, GSIs are billed per request. If provisioned, GSIs require their own provisioned capacity units.