Real-Time Multiversion Concurrency Control Based on Validation Factor

To solve the problem of system overload that is caused by unnecessary transaction restarts with optimistic concurrency control in real-time database systems, avalidation factor (VF) concept and a new method called real-time multiversion concurrency control based on VF (MVOCC-VF) are proposed. By checking the VF, the transaction with higher finished degree is scheduled preferentially. By combining multiversion mechanism, the unnecessary transaction numbers are decreased, especially ensuring the near-to-completed transactions to be accomplished. Theoretical analysis and experimental results demonstrate that the new method can outperform the previous ones.