clickhouse storage tiers

https://www.altinity.com/blog/2019/11/27/amplifying-clickhouse-capacity-with-multi-volume-storage-part-1

multi-volume storage is a feature of ClickHouse starting in version 19.15
The idea is that you store new data on fast storage, like NVMe SSD, and move it later to slower storage, such as high-density disk. Not only does this save on storage, but you can often reduce the overall number of servers without giving up performance.  It’s a double win for efficiency that can reduce hardware costs up to 80% as this example spreadsheet shows. Not surprisingly tiered storage has been a top feature request for years.