Amazon OpenSearch Service announces Star-Tree Index

OpenSearch has introduced Star-Tree Index, a new feature that significantly improves aggregation performance for high-cardinality and multi-dimensional queries. This index pre-aggregates data across configured dimensions and metrics at ingestion time, enabling sub-second response times for frequent aggregations like terms, histogram, and range.

Star-Tree Index is designed for real-time analytics and requires no changes to query syntax; OpenSearch automatically uses the optimized path when supported queries are detected. Early benchmarks show faster aggregation performance on large datasets. This makes it ideal for use cases such as observability, personalization, and time-series dashboards. It works best with append-only data and builds during segment refresh/merge, with minimal impact on ingestion throughput.

Star-Tree Index is available in all regions where OpenSearch 3.1 is supported. The feature is opt-in and can be enabled at index creation time using composite index settings.

Please refer to the AWS Regional Services List for more information about Amazon OpenSearch Service availability. To learn more about Star-Tree Index, see the OpenSearch Documentation