Amazon Timestream is a new time-series database for IoT, edge, and operational applications that can scale to process trillions of time series events per day up to 1,000 times faster than relational databases, and at as low as 1/10th the cost. Amazon Timestream saves customers effort and expense by keeping recent data in memory and moving historical data to a cost-optimized storage tier based upon user-defined policies. Its purpose-built query processing engine gives customers the ability to access and combine recent and historical data transparently across tiers with a single query, without needing to specify explicitly in the query whether the data resides in the in-memory or cost-optimized tier.