If a read item is larger than 4 KB in DynamoDB, what happens to the read capacity units?

In DynamoDB, a read capacity unit represents the amount of read throughput that the table can handle. For a standard read operation, one read capacity unit allows you to read up to 4 KB of data. If a read request exceeds this size limit, the request will use additional read capacity units based on the size of the item being read.

Specifically, for items larger than 4 KB, the calculation is based on the total item size divided by the 4 KB limit. Therefore, if an item is, for example, 8 KB in size, it would require 2 read capacity units because it exceeds the first 4 KB threshold, utilizing another full read capacity unit for the next segment of data. Similarly, if an item is 12 KB in size, it would account for 3 read capacity units.

In conclusion, when an item exceeds the 4 KB limit, it consumes multiple read capacity units calculated as the ceiling of the item size in kilobytes divided by 4 KB. Thus, for an item larger than 4 KB, the system recognizes that it needs additional capacity to fulfill the read request, resulting in the accurate assessment of read capacity units required based on the actual size of the item.