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Three-schema Approach
The three-schema approach, or three-schema concept, in software engineering is an approach to building information systems and systems information management that originated in the 1970s. It proposes three different views in systems development, with conceptual modelling being considered the key to achieving data integration. Overview The three-schema approach provides for three types of schemas with schema techniques based on formal language descriptions: * External schema for user views * Conceptual schema integrates external schemata * Internal schema that defines physical storage structures At the center, the conceptual schema defines the ontology of the concepts as the users think of them and talk about them. The physical schema according to Sowa (2004) "describes the internal formats of the data stored in the database, and the external schema defines the view of the data presented to the application programs." The framework attempted to permit multiple data models to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-2 ANSI-SPARC Three Level Architecture
A coxless four is a rowing boat used in the sport of competitive rowing. It is designed for four persons who propel the boat with sweep oars, without a coxswain. The crew consists of four rowers, each having one oar. There are two rowers on the stroke side (rower's right hand side) and two on the bow side (rower's lefthand side). There is no coxswain, but the rudder is controlled by one of the crew, normally with the rudder cable attached to the toe of one of their shoes which can pivot about the ball of the foot, moving the cable left or right. The steersman may row at bow, who has the best vision when looking over their shoulder, or on straighter courses stroke may steer, since they can point the stern of the boat at some landmark at the start of the course. The equivalent boat when it is steered by a coxswain is called a "coxed four". Racing boats (often called "shells") are long, narrow, and broadly semi-circular in cross-section with gradual tapers, causing little dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A2 3 Three Schema Approach
A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, " a", and its variant " an", are indefinite articles. History The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish it fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object-role Modeling
Object-role modeling (ORM) is used to model the semantics of a universe of discourse. ORM is often used for data modeling and software engineering. An object-role model uses graphical symbols that are based on first order predicate logic and set theory to enable the modeler to create an unambiguous definition of an arbitrary universe of discourse. Attribute free, the predicates of an ORM Model lend themselves to the analysis and design of graph database models in as much as ORM was originally conceived to benefit relational database design. The term "object-role model" was coined in the 1970s and ORM based tools have been used for more than 30 years – principally for data modeling. More recently ORM has been used to model business rules, XML-Schemas, data warehouses, requirements engineering and web forms. History The roots of ORM can be traced to research into semantic modeling for information systems in Europe during the 1970s. There were many pioneers and this shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Systems
An information system (IS) is a formal, sociotechnical, organizational system designed to collect, process, store, and distribute information. From a sociotechnical perspective, information systems are composed by four components: task, people, structure (or roles), and technology. Information systems can be defined as an integration of components for collection, storage and processing of data of which the data is used to provide information, contribute to knowledge as well as digital products that facilitate decision making. A computer information system is a system that is composed of people and computers that processes or interprets information. The term is also sometimes used to simply refer to a computer system with software installed. "Information systems" is also an academic field study about systems with a specific reference to information and the complementary networks of computer hardware and software that people and organizations use to collect, filter, process, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Modeling
Data modeling in software engineering is the process of creating a data model for an information system by applying certain formal techniques. Overview Data modeling is a process used to define and analyze data requirements needed to support the business processes within the scope of corresponding information systems in organizations. Therefore, the process of data modeling involves professional data modelers working closely with business stakeholders, as well as potential users of the information system. There are three different types of data models produced while progressing from requirements to the actual database to be used for the information system.Simison, Graeme. C. & Witt, Graham. C. (2005). ''Data Modeling Essentials''. 3rd Edition. Morgan Kaufmann Publishers. The data requirements are initially recorded as a conceptual data model which is essentially a set of technology independent specifications about the data and is used to discuss initial requirements w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Model
A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner. The term data model can refer to two distinct but closely related concepts. Sometimes it refers to an abstract formalization of the objects and relationships found in a particular application domain: for example the customers, products, and orders found in a manufacturing organization. At other times it refers to the set of concepts used in defining such formalizations: for example concepts such as entities, attributes, relations, or tables. So the "data model" of a banking application may be defined using the entity-relationship "data model". This article uses the term in both senses. A data model explicitly determines th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterprise Architecture Framework
An enterprise architecture framework (EA framework) defines how to create and use an enterprise architecture. An architecture framework provides principles and practices for creating and using the architecture description of a system. It structures architects' thinking by dividing the architecture description into domains, layers, or views, and offers models - typically matrices and diagrams - for documenting each view. This allows for making systemic design decisions on all the components of the system and making long-term decisions around new design requirements, sustainability, and support. Overview Enterprise architecture regards the enterprise as a large and complex system or system of systems. To manage the scale and complexity of this system, an architectural framework provides tools and approaches that help architects abstract from the level of detail at which builders work, to bring enterprise design tasks into focus and produce valuable architecture description doc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zachman Framework
The Zachman Framework is an enterprise ontology and is a fundamental structure for enterprise architecture which provides a formal and structured way of viewing and defining an enterprise. The ontology is a two dimensional classification schema that reflects the intersection between two historical classifications. The first are primitive interrogatives: What, How, When, Who, Where, and Why. The second is derived from the philosophical concept of reification, the transformation of an abstract idea into an instantiation. The Zachman Framework reification transformations are: identification, definition, representation, specification, configuration and instantiation. The Zachman Framework is not a methodology in that it does not imply any specific method or process for collecting, managing, or using the information that it describes; rather, it is an ontology whereby a schema for organizing architectural artifacts (in other words, design documents, specifications, and models) is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IDEF1X
Integration DEFinition for information modeling (IDEF1X) is a data modeling language for the development of semantic data models. IDEF1X is used to produce a graphical information model which represents the structure and semantics of information within an environment or system.FIPS Publication 184 released of IDEF1X by the Computer Systems Laboratory of the National Institute of Standards and Technology (NIST). 21 December 1993. IDEF1X permits the construction of semantic data models which may serve to support the management of data as a resource, the integration of information systems, and the building of computer s. This standard is part of the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Bachman
Charles William Bachman III (December 11, 1924 – July 13, 2017) was an American computer scientist, who spent his entire career as an industrial researcher, developer, and manager rather than in academia. He was particularly known for his work in the early development of database management systems. His techniques of layered architecture include his namesake Bachman diagrams. Biography Charles Bachman was born in Manhattan, Kansas, in 1924, where his father, Charles Bachman Jr., was the head football coach at Kansas State College. He attended high school in East Lansing, Michigan, where his father served as head football coach at Michigan State College from 1933-1946. In World War II he joined the United States Army and spent March 1944 through February 1946 in the South West Pacific Theater serving in the Anti-Aircraft Artillery Corps in New Guinea, Australia, and the Philippine Islands. There he was first exposed to and used fire control computers for aiming 90&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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