https://clickhouse.com/blog/building-a-distributed-cache-for-s3 It's layers all the way down i tell you... I liked this article as it shows the slow evolution into distributed caching that ClickHouse Cloud had to make It highlights the improvements made in order to be able to access hot data, juxtaposing the latency, throughput and IOPS for object storage, SSDs and RAM If the cache disk fills up, the filesystem cache evicts the least recently used data to make room. And because column files in ClickHouse table parts are immutable, there’s generally no need for explicit cache invalidation.