Understanding consistency modes

DynamoDB offers two different data consistency modes to handle different use cases:

• Eventually consistent reads – This is the default.
• Strongly consistent reads

Let's start by learning about eventually consistent reads.

DynamoDB is typically used for cases where data consistency is not critical to the application. For example, website session data can be lost without major impact; the user may have to log in again or they may have to add items back into their shopping cart but unlike a banking transaction, which must fully succeed and be consistent without exception, session data is classified as transient. As a result, DynamoDB defaults to what is called an eventually consistent read. An eventually consistent read means that each read request might not get data that has recently been updated. This is due to how DynamoDB stores its data; it does not wait for the write request to be written to each storage location before...