Updates by Reasoning about States

Georg Lausen, Bertram Ludäscher
Abstract. We present a language extension to Datalog which allows to specify deterministic update procedures in a declarative way. Existing update languages either rely on procedural aspects of program evaluation or leave the framework of deductive databases and logic programming. In contrast, we show that declarative update semantics can be attained by incorporating state terms into the language. Since the resulting language corresponds to a certain class of logic programs, well-known semantics and evaluation techniques can be applied to it.