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Event Condition Action
Event condition action (ECA) is a short-cut for referring to the structure of active rules in event-driven architecture and active database systems. Such a rule traditionally consisted of three parts: *The ''event'' part specifies the signal that triggers the invocation of the rule *The ''condition'' part is a logical test that, if satisfied or evaluates to true, causes the action to be carried out *The ''action'' part consists of updates or invocations on the local data This structure was used by the early research in active databases which started to use the term ECA. Current state of the art ECA rule engines use many variations on rule structure. Also other features not considered by the early research is introduced, such as strategies for event selection into the event part. In a memory-based rule engine, the condition could be some tests on local data and actions could be updates to object attributes. In a database system, the condition could simply be a query to the database ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Event-driven Architecture
Event-driven architecture (EDA) is a software architecture paradigm concerning the production and detection of Event (computing), events. Event-driven architectures are Continuous design, evolutionary in nature and provide a high degree of fault tolerance, performance, and scalability. However, they are complex and inherently challenging to Software testing, test. EDAs are good for complex and dynamic workloads. Overview An ''even'' can be defined as "a significant change in state (computer science), state". For example, when a consumer purchases a car, the car's state changes from "for sale" to "sold". A car dealer's system architecture may treat this state change as an event whose occurrence can be made known to other applications within the architecture. From a formal perspective, what is produced, published, propagated, detected or consumed is a (typically asynchronous) message called the event notification, and not the event itself, which is the state change that triggered the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Database
In computing, an active database is a database that includes an event-driven architecture (often in the form of ECA rules) that can respond to conditions both inside and outside the database. Possible uses include security monitoring, alerting, statistics gathering and authorization. Most modern relational database A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured for ...s include active database features in the form of database triggers. References Types of databases Department of Computer Science, University of Manchester {{Database-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rule Engine
A business rules engine is a software system that executes one or more business rules in a runtime production environment. The rules might come from legal regulation ("An employee can be fired for any reason or no reason but not for an illegal reason"), company policy ("All customers that spend more than $100 at one time will receive a 10% discount"), or other sources. A business rule system enables these company policies and other operational decisions to be defined, tested, executed and maintained separately from application code. Rule engines typically support rules, facts, priority (score), mutual exclusion, preconditions, and other functions. Rule engine software is commonly provided as a component of a business rule management system which, among other functions, provides the ability to: register, define, classify, and manage all the rules, verify consistency of rules definitions (”Gold-level customers are eligible for free shipping when order quantity > 10” and “ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rete Algorithm
The Rete algorithm ( , , rarely , ) is a pattern matching algorithm for implementing rule-based systems. The algorithm was developed to efficiently apply many rules or patterns to many objects, or facts, in a knowledge base. It is used to determine which of the system's rules should fire based on its data store, its facts. The Rete algorithm was designed by Charles L. Forgy of Carnegie Mellon University, first published in a working paper in 1974, and later elaborated in his 1979 Ph.D. thesis and a 1982 paper. Overview A naive implementation of an expert system might check each rule against known facts in a knowledge base, firing that rule if necessary, then moving on to the next rule (and looping back to the first rule when finished). For even moderate sized rules and facts knowledge-bases, this naive approach performs far too slowly. The Rete algorithm provides the basis for a more efficient implementation. A Rete-based expert system builds a network of nodes, where ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ConceptBase
ConceptBase (a.k.a. ConceptBase.cc) is a deductive and object-oriented database management system developed at University of Skövde. Earlier development was done at University of Passau (1987-1992), University of Aachen (1992-2003), and University of Tilburg (1997-2013). It is mainly used for conceptual modeling and metamodeling in the domain of software engineering and related domains. ConceptBase.cc is free and open-source software. ConceptBase combines the following features: * Object-oriented concepts such as classes and inheritance * Deductive rules evaluated by a Datalog engine * Active rules conforming to the event condition action (ECA) paradigm * Recursive function definitions * Metamodeling A metamodel is a model of a model, and metamodeling is the process of generating such metamodels. Thus metamodeling or meta-modeling is the analysis, construction, and development of the frames, rules, constraints, models, and theories applica ... with arbitrarily many abstract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Databases
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term "database" is also used loosely to refer to any of the DBMS, the database system or an application associated with the database. Before digital storage and retrieval of data have become widespread, index cards were used for data storage in a wide range of applications and environments: in the home to record and store recipes, shopping lists, contact information and other organizational data; in business to record presentation notes, project research and notes, and contact information; in schools as flash card ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
