Final answer:
BigQuery does not use fast cached indexes; instead, it focuses on parallel processing and uses techniques like high-performance storage and in-memory caches for query performance optimization.
Step-by-step explanation:
BigQuery uses cached indexes to increase the performance of queries, but it does not use in-memory indexes.
When you run a query in BigQuery, it checks if the results of the query are already in the cache. If they are, it retrieves them from the cache, which is faster than retrieving them from disk. If the results are not in the cache, BigQuery reads the data from disk and saves the results to the cache for future use.
However, it's important to note that the cache is not permanent. BigQuery periodically evicts items from the cache based on a variety of factors, such as popularity and age of the data. So while cached indexes can improve query performance, they are not a guarantee of fast results.