A Formal Characterization of Epsilon Serializability

Epsilon serializability (ESR) is a generalization of classic serializability (SR). In this paper, we provide a precise characterization of ESR when queries that may view inconsistent data run concurrently with consistent update transactions. Our first goal is to understand the behavior of queries in the presence of conflicts and to show how ESR in fact is a generalization of SR. So, using the ACTA framework, we formally express the intertransaction conflicts that are recognized by ESR and through that define ESR, analogous to the manner in which conflict-based serializability is defined. Secondly, expressions are derived for the amount of inconsistency (in a data item) viewed by a query and its effects on the results of a query. These inconsistencies arise from concurrent updates allowed by ESR. Thirdly, in order to maintain the inconsistencies within bounds associated with each query, the expressions are used to determine the preconditions that operations have to satisfy. The results of a query, and the errors in it, depend on what a query does with the (possibly inconsistent) data viewed by it. One of the important byproducts of this work is the identification of different types of queries which lend themselves to an analysis of the effects of data inconsistency on the results of the query.

[1]  Calton Pu,et al.  Autonomous transaction execution with epsilon serializability , 1992, [1992 Proceedings] Second International Workshop on Research Issues on Data Engineering: Transaction and Query Processing.

[2]  Andreas Reuter,et al.  Principles of transaction-oriented database recovery , 1983, CSUR.

[3]  Hector Garcia-Molina,et al.  The case for controlled inconsistency in replicated data , 1990, [1990] Proceedings. Workshop on the Management of Replicated Data.

[4]  Philip S. Yu,et al.  Divergence control for epsilon-serializability , 1992, [1992] Eighth International Conference on Data Engineering.

[5]  Panos K. Chrysanthis,et al.  ACTA: a framework for specifying and reasoning about transaction structure and behavior , 1990, SIGMOD '90.

[6]  Abraham Silberschatz,et al.  An optimistic commit protocol for distributed transaction management , 1991, SIGMOD '91.

[7]  Panos K. Chrysanthis,et al.  In Search of Acceptability Citeria: Database Consistency Requirements and Transaction Correctness properties , 1992, IWDOM.

[8]  Hector Garcia-Molina,et al.  Read-only transactions in a distributed database , 1982, TODS.

[9]  Krithi Ramamritham,et al.  Performance characteristics of epsilon serializability with hierarchical inconsistency bounds , 1993, Proceedings of IEEE 9th International Conference on Data Engineering.

[10]  Abraham Silberschatz,et al.  Unilateral commit: a new paradigm for reliable distributed transaction processing , 1991, [1991] Proceedings. Seventh International Conference on Data Engineering.

[11]  Amit P. Sheth,et al.  Management of interdependent data: specifying dependency and consistency requirements , 1990, [1990] Proceedings. Workshop on the Management of Replicated Data.

[12]  Hector Garcia-Molina,et al.  The Demarcation Protocol: A Technique for Maintaining Linear Arithmetic Constraints in Distributed Database Systems , 1992, EDBT.

[13]  Weimin Du,et al.  Quasi Serializability: a Correctness Criterion for Global Concurrency Control in InterBase , 1989, VLDB.

[14]  Panos K. Chrysanthis,et al.  A Formalism for Extended Transaction Model , 1991, VLDB.

[15]  Henry F. Korth,et al.  Formal model of correctness without serializabilty , 1988, SIGMOD '88.

[16]  Abraham Silberschatz,et al.  Data-valued partitioning and virtual messages (extended abstract) , 1990, PODS '90.

[17]  Abraham Silberschatz,et al.  A theory of relaxed atomicity (extended abstract) , 1991, PODC '91.

[18]  Hector Garcia-Molina,et al.  Coordinating activities through extended sagas: a summary , 1991, COMPCON Spring '91 Digest of Papers.

[19]  Irving L. Traiger,et al.  Granularity of Locks and Degrees of Consistency in a Shared Data Base , 1998, IFIP Working Conference on Modelling in Data Base Management Systems.

[20]  Rafael Alonso,et al.  Data caching issues in an information retrieval system , 1990, TODS.

[21]  Calton Pu,et al.  Replica control in distributed systems: as asynchronous approach , 1991, SIGMOD '91.

[22]  Ahmed K. Elmagarmid,et al.  Maintaining Consistency of Interdependent Data in Multidatabase Systems , 1991 .

[23]  Gio Wiederhold,et al.  Modeling asynchrony in distributed databases , 1987, 1987 IEEE Third International Conference on Data Engineering.

[24]  Abraham Silberschatz,et al.  Data-valued partitioning and virtual messages (extended abstract) , 1990, PODS.

[25]  Abraham Silberschatz,et al.  A Formal Approach to Recovery by Compensating Transactions , 1990, VLDB.

[26]  Panos K. Chrysanthis,et al.  ACTA: The SAGA Continues , 1992, Database Transaction Models for Advanced Applications.

[27]  Patrick E. O'Neil,et al.  The Escrow transactional method , 1986, TODS.

[28]  Hector Garcia-Molina,et al.  Using semantic knowledge for transaction processing in a distributed database , 1983, TODS.

[29]  Arthur J. Bernstein,et al.  Bounded ignorance in replicated systems , 1991, PODS.