Value-cognizant Speculative Concurrency Control
MetadataShow full item record
Citation (published version)Bestavros, Azer; Braoudakis, Spyridon. "Speculative Concurrency Control with Deferred Commitment for Real-Time Databases“, Technical Report BUCS-1995-005, Computer Science Department, Boston University, February 20, 1995. [Available from: http://hdl.handle.net/2144/1566]
A problem with Speculative Concurrency Control algorithms and other common concurrency control schemes using forward validation is that committing a transaction as soon as it finishes validating, may result in a value loss to the system. Haritsa showed that by making a lower priority transaction wait after it is validated, the number of transactions meeting their deadlines is increased, which may result in a higher value-added to the system. SCC-based protocols can benefit from the introduction of such delays by giving optimistic shadows with high value-added to the system more time to execute and commit instead of being aborted in favor of other validating transactions, whose value-added to the system is lower. In this paper we present and evaluate an extension to SCC algorithms that allows for commit deferments.