This project implements mechanisms for cooperation and communication within and between complex database transactions with the aim of increasing the degree of parallelism as well as the level of recovery control during failures. A transaction is defined as a partially ordered set of primitive database operations. The approach exploits the spatial properties of a multidimensional data structure, the Interpolation-Based Grid File (IBGF), which represents objects --points, boxes, or otherwise. It provides a capability to learn important access path information from live processes, prior to accessing the data, and a technique to allow sharing of this information among processes. Throughput will be greatly improved by using this capability to anticipate potential conflicts and to reduce access redundancy. This research will develop servers, responsible for any transaction on the IBGF structure, which incorporate this access path information passing capability. A transaction manager will be built on top of IBGF servers. Methods developed by other researchers will be modified to take advantage of IBGF spatial properties to improve performance. The portability of the results to a commercially available system such as INGRES will be considered. The results provide tools for the design of advanced transaction systems.
