Asynchronous Consistency Restoration under Epsilon Serializability

Many database applications tolerate a certain amount of data inconsistency to gain increased concurrent processing and to accommodate real-world constraints. This paper describes how inconsistency can be modeled in a database and managed with consistency restoration methods. The correctness criterion for the maintenance of inconsistency is epsilon serializability (ESR). An informal notation to characterize inconsistency and several consistency restoration techniques are described. Index terms: epsilon-serializability, divergence control, serializability, crash recovery, consistency restoration, asynchronous transaction processing. 1 Also available as technical report No. HKUST-CS93-002, Department of Computer Science, Hong Kong University of Science and Technology. Contents 1 Introduction 1 2 Consistency in Databases 2 2.1 Transaction Consistency under Serializability : : : : : : : : : : : : : : : : : : : : 2 2.2 Inconsistency between Transactions : : : : : : : : : : : : : : : : :..