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Conceptual Data Model
A conceptual schema or conceptual data model is a high-level description of informational needs underlying the design of a database. It typically includes only the core concepts and the main relationships among them. This is a high-level model with insufficient detail to build a complete, functional database. It describes the structure of the whole database for a group of users. The conceptual model is also known as the data model that can be used to describe the conceptual schema when a database system is implemented. It hides the internal details of physical storage and targets the description of entities, datatypes, relationships and constraints. Overview A conceptual schema is a map of concepts and their relationships used for databases. This describes the semantics of an organization and represents a series of assertions about its nature. Specifically, it describes the things of significance to an organization (''entity classes''), about which it is inclined to collec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database
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 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agile Software Development
Agile software development is an umbrella term for approaches to software development, developing software that reflect the values and principles agreed upon by ''The Agile Alliance'', a group of 17 software practitioners, in 2001. As documented in their ''Manifesto for Agile Software Development'' the practitioners value: * Individuals and interactions over processes and tools * Working software over comprehensive documentation * Customer collaboration over contract negotiation * Responding to change over following a plan The practitioners cite inspiration from new practices at the time including extreme programming, Scrum (software development), scrum, dynamic systems development method, adaptive software development and being sympathetic to the need for an alternative to documentation driven, heavyweight software development processes. Many software development practices emerged from the agile mindset. These agile-based practices, sometimes called ''Agile'' (with a capital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tony Morgan (computer Scientist)
Antony J. (Tony) Morgan (born c. 1944) is a British computer scientist, data modeling consultant, and Professor in computer science at INTI International University. He is known for his work on (2002) "Business rules and information systems," and the 2010 "Information modeling and relational databases," co-authored with Terry Halpin. Life and work Morgan obtained his BA in Earth Sciences from The Open University, his BSc in Computer Systems Engineering from Coventry University, where in 1984 he also obtained his MSc in Control Engineering. In 1988 he obtained his PhD, Computer Science from University of Cambridge with a thesis on automated decision-making using qualitative reasoning."Tony Morgan, Professor at INTI International University," at ''linkedin.com.'' Accessed 02-03-2015. Morgan started his career in industry and worked on "projects in Europe and the US with companies such as Unisys and EDS (now part of Hewlett-Packard) across diverse industries such as Government, Tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terry Halpin
Terence Aidan (Terry) Halpin (born 1950s) is an Australian computer scientist who is known for his formalization of the object–role modeling notation. Biography Born in Australia, Halpin studied at the University of Queensland starting in the 1970s and eventually received a BSc, DipEd, BA, MLitStud and in 1989 a PhD with the thesis "A logical analysis of information systems : static aspects of the data-oriented perspective" under John Staples. In the 1970s he started working at the University of Queensland at the Key Centre for Software Technology at the Department of Computer Science, which he combined with some work in industry on database modeling.Terry Halpin homepage at orm.net. Retrieved 1 October 2008. In the 1990s he moved to industry heading the database research at multiple software companies, including [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Structure Diagram
A data structure diagram (DSD) is the diagram, visual representation of a certain kind of Conceptual schema, data model that contains wikt:entity, entities, their Relational model, relationships, and the Integrity constraints, constraints that are placed on them. It is an older alternative to the entity–relationship model. The basic graphic notation elements of DSDs are boxes which represent entities. Arrow symbols represent relationships. Data structure diagrams are most useful for documenting complex data entities. Overview A data structure diagram is a diagram type that is used to depict the structure of data elements in the data dictionary. The data structure diagram is a graphical alternative to the Object composition, composition specifications within such data dictionary entries. The data structure diagrams is a predecessor of the entity–relationship model (E–R model). In DSDs, Attribute (computing), attributes are specified inside the entity boxes rather than outs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exclusive Relationship (programming)
In computing, an exclusive relationship is a type of Relationship in computer data base 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 analy ... design. In Relational Database Design, in some cases the existence of one kind of relationship type precludes the existence of another. Entities within an entity type A may be related by a relationship type R to an entity in entity type B or entity type C but not both. The relationship types are said to be mutually exclusive. Usually, both relationship types will have the same name. Example A Data (Entity A) could be Sent (Relationship Name) to a Monitor (Entity B) or a Printer (Entity C) to be shown. In this case, the relationship between the Monitor and Printer at one side and Data at the other side is an Exclusive Relationship. Of course it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtyping
In programming language theory, subtyping (also called subtype polymorphism or inclusion polymorphism) is a form of type polymorphism. A ''subtype'' is a datatype that is related to another datatype (the ''supertype'') by some notion of substitutability, meaning that program elements (typically subroutines or functions), written to operate on elements of the supertype, can also operate on elements of the subtype. If S is a subtype of T, the subtyping relation (written as , , or ) means that any term of type S can ''safely be used'' in ''any context'' where a term of type T is expected. The precise semantics of subtyping here crucially depends on the particulars of how ''"safely be used"'' and ''"any context"'' are defined by a given type formalism or programming language. The type system of a programming language essentially defines its own subtyping relation, which may well be trivial, should the language support no (or very little) conversion mechanisms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supertype
In programming language theory, subtyping (also called subtype polymorphism or inclusion polymorphism) is a form of type polymorphism. A ''subtype'' is a datatype that is related to another datatype (the ''supertype'') by some notion of substitutability, meaning that program elements (typically subroutines or functions), written to operate on elements of the supertype, can also operate on elements of the subtype. If S is a subtype of T, the subtyping relation (written as , , or ) means that any term of type S can ''safely be used'' in ''any context'' where a term of type T is expected. The precise semantics of subtyping here crucially depends on the particulars of how ''"safely be used"'' and ''"any context"'' are defined by a given type formalism or programming language. The type system of a programming language essentially defines its own subtyping relation, which may well be trivial, should the language support no (or very little) conversion mechanisms. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Object Oriented
Object-oriented programming (OOP) is a programming paradigm based on the concept of '' objects''. Objects can contain data (called fields, attributes or properties) and have actions they can perform (called procedures or methods and implemented in code). In OOP, computer programs are designed by making them out of objects that interact with one another. Many of the most widely used programming languages (such as C++, Java, and Python) support object-oriented programming to a greater or lesser degree, typically as part of multiple paradigms in combination with others such as imperative programming and declarative programming. Significant object-oriented languages include Ada, ActionScript, C++, Common Lisp, C#, Dart, Eiffel, Fortran 2003, Haxe, Java, JavaScript, Kotlin, Logo, MATLAB, Objective-C, Object Pascal, Perl, PHP, Python, R, Raku, Ruby, Scala, SIMSCRIPT, Simula, Smalltalk, Swift, Vala and Visual Basic.NET. History The idea of "objects" in programm ... [...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 corresponding professional activity is called generally ''data modeling'' or, more specifically, '' database design''. Data models are typically specified by a data expert, data specialist, data scientist, data librarian, or a data scholar. A data modeling language and notation are often represented in graphical form as diagrams. Michael R. McCaleb (1999)"A Conceptual Data Model of Datum Systems". National Institute of Standards and Technology. August 1999. A data model can sometimes be referred to as a data structure, especially in the context of programming languages. Data models are often complemented by function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
