Understanding DynamoDB pricing and limits

DynamoDB is a serverless managed service, which means you do not pick an instance size to control the performance. Instead, DynamoDB is charged based on how much data you read and write to your table. DynamoDB has four main components to its pricing:

• Read request units
• Write request units
• Storage
• Additional features such as DAX, global tables, and streams

Let's start by looking at read and write capacity units.

Request units

Request units are the main usage mechanism within DynamoDB. The number of requests you need for each task will depend on the amount of data being returned as well as the read/write type:

• One read request will give you one strongly consistent read request or two eventually consistent requests for every 4 KB of data.
• Two read requests will give you one transactional read for every 4 KB of data.
• One write request will give you one standard write for every 1 KB of data...