US Patent 9390128 Datastore for storing file access event data

A computer system and method is disclosed for storing large volumes of event data. The system receives access event logs including indications of access events to files stored on a set of storage devices. Each indication includes respective values for a plurality of access event attributes. The system uses the indications to store multiple segment files, each corresponding to a respective subset of the indications. Each segment file stores data as multiple tiles, where each tile includes a compressed copy of those access event indications of the segment file that have a shared value for one of the access event attributes. Each tile is stored contiguously within a set of storage devices.