All Schedules Dynamic

This paper presents the AAected Set Priority Ceiling (ASPC) concurrency control protocol for real-time object-oriented databases. The protocol is based on a combination of a semantic locking technique and priority ceiling techniques. The paper speciies six criteria for real-time concurrency control: high concurrency, deadlock prevention, predictability, temporal consistency enforcement, logical consistency enforcement, and simplicity. It then demonstrates how previous semantic locking techniques and previous priority ceiling protocols each fail to meet several of these criteria, while the ASPC protocol meets all of them except for active temporal consistency support. An implementation, results from synthetic workload tests, and an analysis based on the six criteria are presented for the ASPC protocol.