COLUMNAR CACHING IN TIERED STORAGE

A method comprises storing, within a storage system that is operatively coupled to a server machine that is executing a database server instance that manages a database, a persistent-format copy of a set of data, in a persistent-format, on persistent storage; wherein the set of data is from a table in the database managed by the database server instance. The method further comprises, in response to a load-triggering event, determining a target device in which to construct a mirror-format copy of the set of data, in a mirror-format; wherein the target device is one of the storage system and the server machine; wherein the mirror-format is different than the persistent format; wherein the target device is determined based on (i) metadata associated with the set of data, or (ii) one or more factors. The method further comprises, using data obtained from the persistent-format copy, constructing the mirror-format copy in volatile memory of the target device. One or more computer-readable media and a system comprise corresponding features.