The Search Optimization Service improves query performance by creating and maintaining a persistent data structure called the search access path. This data structure maps column values to specific micro-partitions, enabling Snowflake to efficiently prune irrelevant partitions and scan significantly less data for selective queries. While clustering (A) and micro-partition optimization (D) are general Snowflake performance features, they are not the specific mechanism of the Search Optimization Service. Caching (C) is a separate performance optimization that works differently by storing frequently accessed data in memory.