MyRocks and RocksDB have this concept of column families, which is sort of analogous to a tablespace. Individual tables/partitions/indexes can be placed into different column families. Column families can have different configuration options that impact all data within the column family, the most common options to use would be compression options. We need to document the concept of column families and how to use the rocksdb_default_cf_options and rocksdb_update_cf_options as well as the CREATE/ALTER TABLE/INDEX 'comment' field to set and change column family options. Upstream wiki has some documetation to this effect but IMHO it is a bit fragmented and needs various ideas pulled together into a single document section.