Limitations of customer-defined partition keys

As a Timestream for LiveAnalytics user, it's important to keep in mind the limitations around a customer partition key. Firstly, it requires a good understanding of your workload and query patterns. This means that you should have a clear idea of which dimensions are most frequently use as main filtering conditions in queries and have high cardinality to make the most effective use of partition keys.

Secondly, partition keys need to be defined at the time of table creation and cannot be added to existing tables. This means that you should carefully consider your partitioning strategy before creating a table to ensure that it aligns with your business needs.

Lastly, it's important to note that once the table has been created, you cannot change the partition key afterwards. This means that you should thoroughly test and evaluate your partitioning strategy before committing to it. With these limitations in mind, Timestream's customer-defined partition key can greatly improve query performance and long term satisfaction.