A plurality of virtual files are instantiated in a columnar database. The columnar database includes a columnar data store that persists tables of data contained therein to the plurality of virtual files. Each virtual file is stored in physical data storage and a portion of the virtual file can be cached transiently in a persistence layer intermediate the columnar data store and the physical data storage. The virtual files each comprise a database object for storing data records. Operation are processed, in the columnar database, using the virtual files such that changes to virtual files resulting from the operations of one transaction are isolated from changes on the same virtual files resulting from the operations of other transactions. Related apparatus, systems, techniques and articles are also described.
