Two-Phase Processing Methods
Optimistic concurrency control is a major alternative to locking [KuRo81], but is less suitable than locking in meeting the requirements of DBMSs for high performance transaction processing [Haer84],[Moha92b]. However, there have been many prototyping efforts [Robi82], [KeTe84], [LeRo85], [MuTa85], [Room82], numerous proposals for improved algorithms [MeNa82], [Robi84], [Haer84], [PrSU86], [BCFP87], [FrRT92], and several analyses of optimistic concurrency control performance [MeNa82],[MoWo85],[RyTh87]. Optimistic concurrency control has also been applied to operations on abstract data types [Herl90].
KeywordsConcurrency Control Preemptive Priority Effective Throughput Read Phase Virtual Execution
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- 32.While this is implementation dependent, transaction abort is usually deferred until its next interaction with the concurrency control manager component of the DBMS. Otherwise the concurrency control manager needs to communicate with the resource managers of the system, e.g., to preempt it from the CPU or cancel its disk request.Google Scholar
- 33.This is for a different reason than item (1) in the above list, namely when both transactions have a need to update an object.Google Scholar