We used local database instances in this chapter. The disadvantage of maintaining databases yourself is that you also have to take care of scalability yourself. There are a lot of services that provide popular databases that automatically scale to meet your needs. But not every database can grow without limits: traditional SQL databases often experience speed performance issues when tables become huge. For large datasets, you should choose to use key-value databases (such as NoSQL) that provide scalability by design. In this section, we will explore the usage of DynamoDB, which was created by Amazon, to provide an easily scalable database as a service.

To use AWS services, you need the AWS SDK, but there is no official SDK for Rust, so we will use the rusoto crate, which provides the AWS API in Rust. Let's start by porting the tool, which we created earlier in this chapter, to DynamoDB. First, we should create a table in the DynamoDB instance.