TRANSACTION LENGTH-SENSITIVE LOCKING SCHEME FORLIVELOCK-THIN SCHEDULING IN DATABASE SYSTEMS

摘要

Traditional syntax-oriented serializability notions arernconsidered to be not enough to handle in particularrnvarious types of transaction in terms of duration ofrnexecution. To deal with this situation, altruistic lockingrnhas attempted to reduce delay effect associated with lockrnrelease moment by use of the idea of donation. Anrnimproved form of altruism has also been deployed inrnextended altruistic locking in a way that scope of data tornbe early released is enlarged to include even data initiallyrnnot intended to be donated. In this paper, we first of allrninvestigated limitations inherent in both altruisticrnschemes from the perspective of alleviating starvationrnoccasions for transactions in particular of short-livedrnnature. The idea of two-way donation locking(2DL) hasrnthen been experimented to see the effect of more thanrnsingle donation in distributed database systems.rnSimulation experiments shows that 2DL outperforms thernconventional two-phase locking in terms of the degree ofrnconcurrency and average transaction waiting time.