Application semantics and concurrency control of real-time data-intensive applications

The semantics are discussed of data-intensive real-time applications for which serializability is too recursive for consistency management. By examining the semantics of these applications the authors formalize the concept of similarity which has been used on an ad hoc basis by application engineers to provide more flexibility in concurrency control. Weaker consistency requirements based on the similarity concept are proposed. The concept of similarity is used to extend the usual correctness criteria for transaction scheduling: finite-state, view, conflict serializability to their counterparts of final-state Δ-serializability, view Δ-serializability, and conflict Δ-serializability