How to use partition keys effectively in Amazon Keyspaces

The primary key that uniquely identifies each row in an Amazon Keyspaces table can consist of one or multiple partition key columns, which determine which partitions the data is stored in, and one or more optional clustering column, which define how data is clustered and sorted within a partition.

Because the partition key establishes the number of partitions your data is stored in and how the data is distributed across these partitions, how you chose your partition key can have a significant impact upon the performance of your queries. In general, you should design your application for uniform activity across all partitions on disk.

Distributing read and write activity of your application evenly across all partitions helps to minimize throughput costs and this applies to on-demand as well as provisioned read/write capacity modes. For example, if you are using provisioned capacity mode, you can determine the access patterns that your application needs, and estimate the total read capacity units (RCU) and write capacity units (WCU) that each table requires. Amazon Keyspaces supports your access patterns using the throughput that you provisioned as long as the traffic against a given partition does not exceed 3,000 RCUs and 1,000 WCUs.

Amazon Keyspaces offers additional flexibility in your per-partition throughput provisioning by providing burst capacity, for more information see Using burst capacity effectively in Amazon Keyspaces.