Abstract: Textbook treatments of database concurrency control concentrate on serialization theory and on locking or timestamp-based implementations. In practice, few applications use these mechanisms, because of their excessive
impact on performance. Every common platform provides as default behaviour, something less safe than serializable isolation! Indeed, in some of the most widespread products, even declaring an application as "SERIALIZABLE" does not guarantee that this will happen; instead these platforms use a concurrency control mechanisms called Snapshot Isolation, which can lead to data inconsistencies. After a brief review of traditional concurrency control, this lecture presents recent discoveries about isolation mechanisms that are called "weak" because they do not always ensure serializability. The final topic covers the interactions between weak isolation and database replication.

Bio: Alan Fekete completed a PhD in Mathematics at Harvard University in 1987, after an undergraduate education in Computer Science and Mathematics at Sydney University in Australia. He has been an academic in Computer Science at Sydney since 1988, and he has held visiting appointments at Cornell, MIT, UWashington and Microsoft Research. His research is focussed on the use of formal methods to understand infrastructure ³systems² software, especially database transaction management. Fekete is recognized as a Distinguished Scientist by the ACM, he has served on program committees for VLDB, SIGMOD and PODS, and he has supervised 11 completed PhD students.