Performance characteristics of epsilon serializability with hierarchical inconsistency bounds

Abstract

The notion of hierarchical inconsistency bounds that allows inconsistency to be specified at different granularities-with transactions being at the top of the hierarchy, objects at the bottom, and groups in between-is introduced. The mechanisms needed to control the inconsistency so that it lies within the specified bounds are described. The performance improvement due to epsilon serializability (ESR) is evaluated. Two important observations are made. First, the thrashing point shifts to a higher multiprogramming level when transaction inconsistency bounds are increased. Second, for a particular multiprogramming level and a particular transaction inconsistency bound, the throughput does not increase with increasing object inconsistency bounds but peaks at some intermediate value.