检索结果-内蒙古大学图书馆

Automated construction of fuzzy event sets and its application to active databases

IEEE TRANSACTIONS ON FUZZY SYSTEMS 2001年第3期9卷 450-460页

作者： Saygin, Y Ulusoy, Ö Bilkent Univ Dept Comp Engn TR-06533 Ankara Turkey

Fuzzy sets and fuzzy logic research aims to bridge the gap between the crisp world of math and the real world. Fuzzy set theory was applied to many different areas, from control to databases. Sometimes the number of events in an event-driven system may become very high and unmanageable. Therefore, it is very useful to organize the events into fuzzy event sets also introducing the benefits of the fuzzy set theory, All the events that have occurred in a system can be stored in event histories which contain precious hidden information, In this paper, we propose a method for automated construction of fuzzy event sets out of event histories via data mining techniques. The useful information hidden in the event history is extracted into a matrix called sequential proximity matrix. This matrix shows the proximities of events and it is used for fuzzy rule execution via similarity based event detection and construction of fuzzy event sets. Our application platform is active databases. We describe how fuzzy event sets can be exploited for similarity based event detection and fuzzy rule execution in active database systems.

关键词： active databases fuzzy event sets fuzzy rule execution fuzzy triggers similarity based event detection

来源：评论

学校读者我要写书评

暂无评论

ARCHITECTURES AND MONITORING TECHNIQUES FOR active databases - AN EVALUATION

引用

DATA & KNOWLEDGE ENGINEERING 1995年第1期16卷 1-26页

作者： CHAKRAVARTHY, S Database Systems Research and Development Center Computer and Information Sciences Department University of Florida Gainesville FL 32611 USA

The need for active capability for non-traditional applications and its concomitant benefits are well-established. Although the event-based technique for monitoring conditions (leading to the integrated architecture) is the most versatile of all the techniques, from a practical viewpoint there is a need for enhancing pre-existing non-active DBMSs to support active capability. The set of techniques that can be used for providing this add-on active capability (leading to the layered architecture) imposes certain limitations on the extent of active capability that can be supported. Insights into the details of techniques as well as their impact on the architecture entails a design that better meets the active database objectives. This paper identifies a repertoire of techniques for condition monitoring and discusses their suitability to different architectures. This paper argues that from a pragmatic viewpoint, both layered and integrated approaches to support active capability need to be pursued. Then it compares polling and event-based or asynchronous monitoring techniques using an implementation on Symbolics using Common Lisp with Flavors. The focus of this comparison is on: techniques, performance, influence of implementation strategies on performance, and identification of opportunities for optimization.

关键词： active databases POLLING PERFORMANCE EVALUATION IMPLEMENTATION STRATEGIES LAYERED APPROACH OBJECT-ORIENTED DESIGN

来源：评论

学校读者我要写书评

暂无评论

Selection predicate indexing for active databases using interval skip lists

引用

INFORMATION SYSTEMS 1996年第3期21卷 269-298页

作者： Hanson, EN Johnson, T Computer and Information Science and Engineering Department University of Florida Gainesville FL 32611-6120 USA

A new, efficient selection predicate indexing scheme for active database systems is introduced. The selection predicate index proposed uses an interval index on an attribute of a relation or object collection when one or more rule condition clauses are defined on that attribute. The selection predicate index uses a new type of interval index called the interval skip list (IS-list). The IS-list is designed to allow efficient retrieval of all intervals that overlap a point, while allowing dynamic insertion and deletion of intervals. IS-list algorithms are described in detail. The IS-list allows efficient on-line searches, insertions, and deletions, yet is much simpler to implement than other comparable interval index data structures such as the priority search tree and balanced interval binary search tree (IBS-tree). IS-lists require only one third as much code to implement as balanced IBS-trees. The combination of simplicity, performance, and dynamic updateability of the IS-list is unmatched by any other interval index data structure. This makes the IS-list a good interval index structure for implementation in an active database predicate index.(double dagger)

关键词： active databases triggers predicate indexing interval skip lists discrimination networks

来源：评论

学校读者我要写书评

暂无评论

Self-tuning of the relationships among rules' components in active databases systems

引用

IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING 2004年第3期16卷 375-379页

作者： Botzer, D Etzion, O IBM Res Lab Haifa IL-31905 Haifa Israel

active databases systems are systems that detect events and trigger actions as a result of this detection. active capabilities are provided by a set of rules, such that each rule consists of three components (event, condition, and action). A major performance issue in active databases is the issue of relationships among rule components. Current implementations of triggers do not allow flexibility in the selection of transaction policies (partition of rules to transactions);the intertransaction timing policies of rules' components, the intratransaction policies of commit and abort dependencies, and synchronization issues. While these decisions have a substantial impact on the application performance, they are not provided as design primitives;one of the reasons for that is that it is very difficult to manually tune these decisions. In some research prototypes of active databases, these relationships are encapsulated into a set of coupling modes. Each coupling mode represents a combination of decisions about the partition of rule components to transactions, the relative timing within a transaction, and the interrelationships among these transactions. This paper describes a self-tuning model that operates on a general active database. The optimization model strives to minimize a programmable goal function that reflects the system designer's preferences and the system behavior and the applications' semantics through constraint definitions. The tuning model strives to optimize the mutual relationships among the system rules' components.

关键词： active databases advanced transaction models databases optimization tuning

来源：评论

学校读者我要写书评

暂无评论

Effective scheduling of detached rules in active databases

引用

IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING 2003年第1期15卷 2-13页

作者： Ceri, S Gennaro, C Paraboschi, S Serazzi, G Politecn Milan Dipartimento Elettron & Informat I-20133 Milan Italy CNR Ist Elaborazione Informaz I-56124 Pisa Italy Univ Studi Bergamo Dipartimento Ingn I-24044 Dalmine BG Italy

While triggers have become a classical ingredient of relational database systems, research in active databases is aiming at extending the functionality and expressive power of active rules beyond the scope of relational triggers, One of the most important current trend concerns the support of detached active rules, i.e., of rules which are executed as separate transactions, running outside of the scope of the transaction which generates the triggering event. Detached rules have important applications in workflow management and global integrity maintenance across transactions. One of the main issues in designing the rule engine for detached rules is determining their optimal scheduling. In this paper, we study the performance of a detached rule scheduler whose objective is to minimize the interference of detached rule execution with regard to the normal transactional load, This objective is achieved by executing detached rules at given periods of time and by assigning them a fixed amount of dedicated threads we study the performance of the scheduler relative to the two most critical design parameters, the frequency of execution of the scheduler, and the number of dedicated execution threads.

关键词： active databases detached rules rule scheduling

来源：评论

学校读者我要写书评

暂无评论

Concurrent rule execution in active databases

引用

INFORMATION SYSTEMS 1998年第1期23卷 39-64页

作者： Saygin, Y Ulusoy, O Chakravarthy, S Bilkent Univ Dept Comp Sci & Informat Engn Bilkent Turkey Univ Florida Dept Comp Sci & Informat Engn Gainesville FL 32611 USA

An active DBMS is expected to support concurrent as well as sequential, rule execution in an efficient manner. Nested transaction model is a suitable tool to implement rule execution as it can handle nested rule firing and concurrent rule execution well. In this paper, we describe a concurrent rule execution model based on parallel nested transactions. We discuss implementation details of how the flat transaction model of OpenOODB has been extended by using Solaris threads in order to support concurrent execution of rules. Copyright (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

关键词： active databases nested transactions rule execution

来源：评论

学校读者我要写书评

暂无评论

SNOOP - AN EXPRESSIVE EVENT SPECIFICATION LANGUAGE FOR active databases

引用

DATA & KNOWLEDGE ENGINEERING 1994年第1期14卷 1-26页

作者： CHAKRAVARTHY, S MISHRA, D TEKNEKRON COMMUN SYST INC BERKELEYCA 94704

Making a database system active to meet the requirements of a wide range of applications entails developing an expressive event specification language and its implementation. Extant systems support mostly database events and in some cases a few predefined events. This paper discusses an event specification language (termed Snoop) for active databases. We define an event, distinguish between events and conditions, classify events into a class hierarchy, identify primitive events, and introduce a small number of event operators for constructing composite (or complex) events. Snoop supports temporal, explicit, and composite events in addition to the traditional database events. The novel aspect of our work lies not only in supporting a rich set of events and event expressions, but also in the notion of parameter contexts. Essentially, parameter contexts augment the semantics of composite events for computing their parameters. For concreteness, we present parameter computation for the relational model. Finally, we show how a contingency plan that includes time constraints can be supported without stepping outside of the framework proposed in this paper.

关键词： EVENT SPECIFICATION PRIMITIVE AND COMPOSITE EVENTS CONTINGENCY PLAN PARAMETER CONTEXTS active databases

来源：评论

学校读者我要写书评

暂无评论

TEMPORAL TRIGGERS IN active databases

引用

IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING 1995年第3期7卷 471-486页

作者： SISTLA, AP WOLFSON, O Department of Electrical Engineering and Computer Science University of Illinois Chicago IL USA

In this paper we propose two languages, called Future Temporal Logic (FTL) and Past Temporal Logic (PTL), for specifying temporal triggers. Some examples of trigger conditions that can be specified in our language are the following: ''The value of a certain attribute increases by more than 10% in 10 minutes,'' ''A tuple that satisfies a certain predicate is added to the database at least 10 minutes before another tuple, satisfying a different condition, is added to the database.'' Such triggers are important for monitor and control applications. In addition to the languages, we present algorithms for processing the trigger conditions specified in these languages, namely, procedures for determining when the trigger conditions are satisfied. These methods can be added as a ''temporal'' component to an existing database management systems. A preliminary prototype of the temporal component that uses the FTL language has been built on top of Sybase running on SUN workstations.

关键词： active databases TRIGGERS TEMPORAL LOGICS ALGORITHMS

来源：评论

学校读者我要写书评

暂无评论

Analysis and optimization of active databases

引用

DATA & KNOWLEDGE ENGINEERING 2002年第3期40卷 241-271页

作者： Montesi, D Torlone, R Univ Bologna DSI I-40127 Bologna Italy Univ Roma Tre DIA I-00146 Rome Italy

We introduce a new formal semantics for active databases that relies on a transaction rewriting technique. A user-defined transaction, which is viewed here as a sequence of atomic database updates forming a semantic atomic unit, is translated by means of active rules into induced one(s). These transactions embody active rule semantics which can be either immediate or deferred. Rule semantics, confluence, equivalence and optimization are then formally investigated and characterized in a solid framework that naturally extends a known model for relational database transactions. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： active databases rule semantics transaction equivalence confluence optimization

来源：评论

学校读者我要写书评

暂无评论

SnoopIB: Interval-based event specification and detection for active databases

引用

DATA & KNOWLEDGE ENGINEERING 2006年第1期59卷 139-165页

作者： Adaikkalavan, Raman Chakravarthy, Sharma Univ Texas Dept Comp Sci & Engn Informat Technol Lab Arlington TX 76019 USA

Detection-based semantics does not differentiate between,vent detection and event occurrence and has been used for detecting events in most of the active systems that support Event-Condition-Action rules. However, this is a limitation for many applications that require interval-based semantics. In this article, we formalize the detection of Snoop (an event specification language) event operators using interval-based semantics (termed SnoopIB) in various event consumption modes. We show how events are detected using event detection graphs, and present a few representative algorithms to detect SnooplB operators and comment on their implementation in the context of Sentinel-an active object-oriented DBMS. (c) 2005 Elsevier B.V. All rights reserved.

关键词： active databases ECA rules interval-based semantics event specification event detection

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：