Temporal Conditions with Retroactive and ProactiveUpdatesFebruary
نویسندگان
چکیده
In this paper, we extend the temporal rule language introduced in 1] to support pro-and retroactive updates. Such updates may cause the time when a condition is satissed to diier from the time when it is detected. We enrich the rule language by providing a set of alternative actions in each rule; this allows execution of one of the alternative actions depending on the diierence between condition-satisfaction time and detection time. We identify a subset of the temporal condition language PTL 1], called decomposable PTL, that is amenable to more eecient evaluation. We present an evaluation algorithm for decomposable PTL. We also describe the implementation of the system on top of the Sybase DBMS.
منابع مشابه
An Efficient Approach for Detecting and Repairing Data Inconsistencies Resulting from Retroactive Updates in Multi-temporal and Multi-version XML Databases
Multi-temporal XML databases supporting schema versioning contain XML elements of different temporal formats (snapshot, transaction-time, valid-time, and bitemporal), defined under several XML schema versions. These databases support three types of data updates concerned with the time when updates are made: retroactive, proactive, or on-time, dealing with past, future, or current data respectiv...
متن کاملMemory Without Consolidation: Temporal Distinctiveness Explains Retroactive Interference
Is consolidation needed to account for retroactive interference in free recall? Interfering mental activity during the retention interval of a memory task impairs performance, in particular if the interference occurs in temporal proximity to the encoding of the to-be-remembered (TBR) information. There are at least two rival theoretical accounts of this temporal gradient of retroactive interfer...
متن کاملUpdating Atomic Information in Labelled Database Systems ( Extended Abstract )
This paper investigates the applications of Labelled Deductive Systems (LDS) as a framework for the development of a computational formalism for the description of active historical databases. This formalism is then applied to the study of retroactive updates. The propositional temporal logic USV/'Z for temporal validity is presented and we prove its soundness and completeness. The historical d...
متن کاملUpdating Atomic Information in Labelled Database Systems ( Extended
This paper investigates the applications of Labelled Deductive Systems (LDS) as a framework for the development of a computational formalism for the description of active historical databases. This formalism is then applied to the study of retroactive updates. The propositional temporal logic USV/Z for temporal validity is presented and we prove its soundness and completeness. The historical da...
متن کاملA Retrospective Analysis of Time Concepts in Temporal Databases
In this paper, we propose a formal de nition of temporal validity which we believe is the rst and the most comprehensive quanti cation of that notion. The temporal validity is developed into the notion of sort of validity with which the confusion among various time concepts introduced for temporal databases can be dispelled. Further, we discuss the problem of preserving multiple past states of ...
متن کامل