The Starburst Long Field Manager

Starburst is an experimental database management system prototype whose objectives include extensibility, support for knowledge databases, use of memory-resident database techniques, and support for large objects. We describe the structure of the Starburst long field manager, which was designed to manage large database objects such as voice, image, sound and video. The long field manager uses the buddy system for managing disk space, which allows it to allocate a range of small to very large disk extents (buddy segments) quickly and efficiently. When possible, a small number of large buddy segments are used to store long fields, which allows the long field manager to perform fewer disk seeks when transferring large objects to and from disk. The long field manager uses shadow-based recovery for long field data and write-ahead-log recovery for long field descriptor and allocation data. Internal space management synchronization is enforced by a combination of long-term and instantaneous locks.