Disk-Resident Streaming Dictionary

A method, apparatus and computer program product for storing data in a disk storage system is presented. A dictionary data structure is defined and stored on the disk storage system. Key-value pairs can be inserted and deleted into the dictionary data structure, with full transactional semantics, at a rate that is faster than one insertion per disk-head movement. Keys can be looked up with only a logarithmic number of transfers, even for keys that have been recently inserted or deleted. Queries can be performed on ranges of key-value pairs, including recently inserted or deleted pairs, at a constant fraction of the bandwidth of the disk. The dictionary employs indirect logging for physical block logging.