A financial firm runs Amazon Athena against a petabyte-scale dataset for a BI application. A nightly AWS Glue job refreshes the data once per day, while the BI app requires hourly refreshes for policy reasons. The goal is to reduce Athena costs without adding infrastructure and with minimal operational overhead. What is the best option?

The query result reuse feature of Amazon Athena allows Athena to use results from previous identical queries for up to 60 minutes, significantly reducing query costs by avoiding re-scanning data. This directly addresses the need for hourly refreshes while minimizing operational overhead and without adding new infrastructure. Moving data to S3 Glacier Deep Archive would make the data inaccessible for immediate Athena queries, violating the BI application's requirements. Adding an ElastiCache cluster would introduce new infrastructure and operational overhead, which the question explicitly seeks to avoid. Changing the file format to Apache Parquet is a good practice for performance and cost optimization but would require a data transformation process, adding operational overhead and not directly addressing the hourly refresh cost issue as efficiently as query result reuse.