What type of read does a read capacity unit represent for items up to 4 KB in size?

A read capacity unit represents the amount of throughput that a user can consume from a DynamoDB table. For items that are 4 KB or smaller, one read capacity unit corresponds to one strongly consistent read per second. A strongly consistent read returns the most up-to-date data, reflecting all writes that occurred up to the moment of the read.

This type of read ensures that the result is the current state of the item, which is critical for applications that require immediate consistency, such as financial transactions or real-time data analysis. In contrast, an eventual consistent read, which returns data that may not reflect the most recent write, can use half the capacity, allowing two eventual consistent reads per second for items up to 4 KB in size.

Understanding the distinctions between strongly consistent and eventually consistent reads is crucial for optimizing throughput and managing costs in applications that use Amazon DynamoDB. The read capacity units are designed to help developers plan their access patterns based on the consistency requirements of their applications.