Article thumbnail

Weak Consistency: A Generalized Theory and Optimistic Implementations for Distributed Transactions

By Atul Adya


Current commercial databases allow application programmers to trade off consistency for performance. However, existing definitions of weak consistency levels are either imprecise or they disallow efficient implementation techniques such as optimism. Ruling out these techniques is especially unfortunate because commercial databases support optimistic mechanisms. Furthermore, optimism is likely to be the implementation technique of choice in the geographically distributed and mobile systems of the future. This thesis presents the first implementation-independent specifications of existing ANSI isolation levels and a number of levels that are widely used in commercial systems, e.g., Cursor Stability, Snapshot Isolation. It also specifies a variety of guarantees for predicate-based operations in an implementation-independent manner. Two new levels are defined that provide useful consistency guarantees to application writers; one is the weakest level that ensures consistent reads, while the other captures some useful consistency properties provided by pessimistic implementations. W

Year: 1999
OAI identifier: oai:CiteSeerX.psu:
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.