DynamoDB
DynamoDB is Amazon’s managed nonrelational database service. It’s designed for highly transactional applications that need to read from or write to a database tens of thousands of times a second.
Items and Tables
The basic unit of organization in DynamoDB is an item, which is analogous to a row or record in a relational database. DynamoDB stores items in tables. Each DynamoDB table is stored across one or more partitions. Each partition is backed by solid-state drives, and partitions are replicated across multiple Availability Zones in a region, giving you a monthly availability of 99.99 percent.
Each item must have a unique value for the primary key. An item can also consist of other key-value pairs called attributes. Each item can store up to 400 KB of data, more than enough to fill a book! To understand this better, consider the sample shown in Table 9.2.
TABLE 9.2 A Sample DynamoDB Table
| Username (Primary Key) | LastName | FirstName | FavoriteColor |
| hburger... |