Integrated predicative synchronization implemented in a federated DBMS

The author compares predicative locking and predicative validation and shows that predicative locking is superior to predicative validation if many conflicts occur, whereas predicative validation performs better if no conflicts occur. To combine the advantages of both synchronization methods and to avoid their disadvantages, the author has developed integrated synchronization. Integrated synchronization uses a fast heuristics and schedules pairs of operations depending on their conflict probability. Pairs of operations with a low conflict probability, i.e. pairs of tuple operations, are validated against each other, whereas pairs of operations with a high conflict probability, i.e. pairs including at least one set-oriented operation, are synchronized by predicative locking. Furthermore, the author has implemented all three synchronization strategies, predicative locking, predicative validation, and the integrated synchronization, within the federated DBPL database system and compared their performance. The result shows that integrated synchronization is superior to both predicative locking and predicative validation