DEA-C01 Data Operations and Support Practice Question

Correct answer & explanation

When read traffic spikes above the maximum auto-scaling limit of 10,000 RCUs (e.g., to 12,000 RCUs), the table cannot provision enough read capacity units quickly enough. This leads to throttling of requests. The AWS SDKs are designed to retry throttled requests, and under certain conditions, they may fall back to eventually consistent reads to reduce latency, which can return stale data. This explains why stale data appears even when the application explicitly requests strongly consistent reads. Option B is incorrect: write sharding does not inherently cause read-after-write inconsistencies; DynamoDB's strong consistency guarantees hold if capacity is sufficient. Option C is incorrect: DAX is a caching layer that provides eventual consistency by default; strongly consistent reads bypass DAX and go directly to the table, so DAX is not involved. Option D is incorrect: global tables replicate data asynchronously, but the statement says the application uses a single table; moreover, reading from a replica region would use eventually consistent reads only if configured, but the question states strongly consistent reads are used.