Errors in ‘process synchronization in database systems’

Abstract

This paper disproves several results pertaining to database concurrency control that are claimed in [8]. The results we disprove are•theorems 3.1, 3.2, 3.6 -- which claim a polynomial time algorithm for testing whether transaction schedules are serializable, and•theorems 4.2 and 4.7 -- which claim a necessary and sufficient mechanism for preserving the “weak consistency” of databases. In addition, we demonstrate that the notion of “weak consistency” introduced in [8] admits database states that are strictly inconsistent. © 1981, ACM. All rights reserved.