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Duplication Is Evil
"Don't repeat yourself" (DRY) is a principle of software development aimed at reducing repetition of software patterns, replacing it with abstractions or using data normalization to avoid redundancy. The DRY principle is stated as "Every piece of knowledge must have a single, unambiguous, authoritative representation within a system". The principle has been formulated by Andy Hunt and Dave Thomas in their book ''The Pragmatic Programmer''. They apply it quite broadly to include " database schemas, test plans, the build system, even documentation". When the DRY principle is applied successfully, a modification of any single element of a system does not require a change in other logically unrelated elements. Additionally, elements that are logically related all change predictably and uniformly, and are thus kept in sync. Besides using methods and subroutines in their code, Thomas and Hunt rely on code generators, automatic build systems, and scripting languages to observe t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle
A principle is a proposition or value that is a guide for behavior or evaluation. In law, it is a Legal rule, rule that has to be or usually is to be followed. It can be desirably followed, or it can be an inevitable consequence of something, such as the laws observed in nature or the way that a system is constructed. The principles of such a system are understood by its users as the essential characteristics of the system, or reflecting system's designed purpose, and the effective operation or use of which would be impossible if any one of the principles was to be ignored. A system may be explicitly based on and implemented from a document of principles as was done in IBM's IBM System/360 architecture, 360/370 ''Principles of Operation''. Examples of principles are, entropy (other), entropy in a number of fields, least action in physics, those in descriptive comprehensive and fundamental law: doctrines or assumptions forming normative rules of conduct, separation of chur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kent C
Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces the French department of Pas-de-Calais across the Strait of Dover. The county town is Maidstone. It is the fifth most populous county in England, the most populous non-Metropolitan county and the most populous of the home counties. Kent was one of the first British territories to be settled by Germanic tribes, most notably the Jutes, following the withdrawal of the Romans. Canterbury Cathedral in Kent, the oldest cathedral in England, has been the seat of the Archbishops of Canterbury since the conversion of England to Christianity that began in the 6th century with Saint Augustine. Rochester Cathedral in Medway is England's second-oldest cathedral. Located between London and the Strait of Dover, which separates England from mainland Europ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk Mirroring
In data storage, disk mirroring is the replication of logical disk volumes onto separate physical hard disks in real time to ensure continuous availability. It is most commonly used in RAID 1. A mirrored volume is a complete logical representation of separate volume copies. In a disaster recovery context, mirroring data over long distance is referred to as storage replication. Depending on the technologies used, replication can be performed synchronously, asynchronously, semi-synchronously, or point-in-time. Replication is enabled via microcode on the disk array controller or via server software. It is typically a proprietary solution, not compatible between various data storage device vendors. Mirroring is typically only synchronous. Synchronous writing typically achieves a recovery point objective (RPO) of zero lost data. Asynchronous replication can achieve an RPO of just a few seconds while the remaining methodologies provide an RPO of a few minutes to perhaps several hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denormalization
Denormalization is a strategy used on a previously- normalized database to increase performance. In computing, denormalization is the process of trying to improve the read performance of a database, at the expense of losing some write performance, by adding redundant copies of data or by grouping data.S. K. Shin and G. L. SandersDenormalization strategies for data retrieval from data warehouses Decision Support Systems, 42(1):267-282, October 2006. It is often motivated by performance or scalability in relational database software needing to carry out very large numbers of read operations. Denormalization differs from the unnormalized form in that denormalization benefits can only be fully realized on a data model that is otherwise normalized. Implementation A normalized design will often "store" different but related pieces of information in separate logical tables (called relations). If these relations are stored physically as separate disk files, completing a database qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Normalization
Database normalization or database normalisation (see spelling differences) is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by British computer scientist Edgar F. Codd as part of his relational model. Normalization entails organizing the columns (attributes) and tables (relations) of a database to ensure that their dependencies are properly enforced by database integrity constraints. It is accomplished by applying some formal rules either by a process of ''synthesis'' (creating a new database design) or ''decomposition'' (improving an existing database design). Objectives A basic objective of the first normal form defined by Codd in 1970 was to permit data to be queried and manipulated using a "universal data sub-language" grounded in first-order logic. An example of such a language is SQL, though it is one that Codd regarded as seriou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copy And Paste Programming
Copy may refer to: * Copying or the product of copying (including the plural "copies"); the duplication of information or an artifact ** Cut, copy and paste, a method of reproducing text or other data in computing ** File copying **Photocopying, a process which makes paper copies of documents and other visual images **Fax, a telecommunications technology used to transfer facsimile copies of documents, especially over the telephone network ** Facsimile, a copy or reproduction that is as true to the original source as possible ** Replica, a copy closely resembling the original concerning its shape and appearance **Term of art in U.S. copyright law meaning a material object in which a work of authorship has been embodied, such as a book * Copy (command), a shell command on DOS and Windows systems *Copy (publishing), written content in publications, in contrast to photographs or other elements of layout. **The output of journalists and authors, ready for copy editing and typesetting * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Reuse
In software development (and computer programming in general), code reuse, also called software reuse, is the use of existing software, or software knowledge, to build new software, following the reusability principles. Code reuse may be achieved by different ways depending on a complexity of a programming language chosen and range from a lower-level approaches like code copy-pasting (e.g. via snippets), simple functions ( procedures or subroutines) or a bunch of objects or functions organized into modules (e.g. libraries) or custom namespaces, and packages, frameworks or software suites in higher-levels. Code reuse implies dependencies which can make code maintanability harder. At least one study found that code reuse reduces technical debt. Overview Ad hoc code reuse has been practiced from the earliest days of programming. Programmers have always reused sections of code, templates, functions, and procedures. Software reuse as a recognized area of study in software eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Duplication
In computer programming, duplicate code is a sequence of source code that occurs more than once, either within a program or across different programs owned or maintained by the same entity. Duplicate code is generally considered undesirable for a number of reasons. A minimum requirement is usually applied to the quantity of code that must appear in a sequence for it to be considered duplicate rather than coincidentally similar. Sequences of duplicate code are sometimes known as code clones or just clones, the automated process of finding duplications in source code is called clone detection. Two code sequences may be duplicates of each other without being character-for-character identical, for example by being character-for-character identical only when white space characters and comments are ignored, or by being token-for-token identical, or token-for-token identical with occasional variation. Even code sequences that are only functionally identical may be considered duplicate cod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstraction Principle (programming)
In software engineering and programming language theory, the abstraction principle (or the principle of abstraction) is a basic dictum that aims to reduce duplication of information in a program (usually with emphasis on code duplication) whenever practical by making use of abstractions provided by the programming language or software libraries . The principle is sometimes stated as a recommendation to the programmer, but sometimes stated as a requirement of the programming language, assuming it is self-understood why abstractions are desirable to use. The origins of the principle are uncertain; it has been reinvented a number of times, sometimes under a different name, with slight variations. When read as recommendations to the programmer, the abstraction principle can be generalized as the "don't repeat yourself" (DRY) principle, which recommends avoiding the duplication of information in general, and also avoiding the duplication of human effort involved in the software developmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cher Scarlett
Cher Scarlett (born ) is an American software engineer and writer. She is a workers' rights activist and has organized staff at Apple, Activision Blizzard, and Starbucks. Scarlett, who has bipolar disorder, experienced struggles in her early life, leading her to drop out of high school and attempt to overdose. Self-taught web development skills from her adolescence in the late 1990s allowed her to overcome a lack of formal education and build a software engineering career after the birth of her child. Scarlett's experiences and observations in a male-dominated occupation led her to become a workers' rights advocate and critic of technology and corporations. She was a leader of the #AppleToo movement, which gathered and shared stories of mistreatment from current and former Apple employees, and was a founder of Apple Together, a solidarity union, where she remains an advisor. Scarlett also filed complaints against Apple with the National Labor Relations Board and U.S. Securitie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twitter
Twitter is an online social media and social networking service owned and operated by American company Twitter, Inc., on which users post and interact with 280-character-long messages known as "tweets". Registered users can post, like, and 'Reblogging, retweet' tweets, while unregistered users only have the ability to read public tweets. Users interact with Twitter through browser or mobile Frontend and backend, frontend software, or programmatically via its APIs. Twitter was created by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams (Internet entrepreneur), Evan Williams in March 2006 and launched in July of that year. Twitter, Inc. is based in San Francisco, California and has more than 25 offices around the world. , more than 100 million users posted 340 million tweets a day, and the service handled an average of 1.6 billion Web search query, search queries per day. In 2013, it was one of the ten List of most popular websites, most-visited websites and has been de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vox Media
Vox Media, Inc. is an American mass media company based in Washington, D.C., and New York City. The company was established in November 2011 by Jim Bankoff and Trei Brundrett to encompass ''SB Nation'' (a sports blog network founded in 2005 by Tyler Bleszinski, Markos Moulitsas, and Jerome Armstrong) and ''The Verge'' (a technology news website launched alongside Vox Media). Bankoff had been the CEO for ''SB Nation'' since 2009. Vox Media owns editorial brands, primarily ''The Verge'', ''Vox (website), Vox'', ''SB Nation'', ''Eater (website), Eater'', ''Polygon (website), Polygon'', and ''New York (magazine), New York''. ''New York'' further incorporates the websites ''Intelligencer'', ''The Cut'', ''Vulture'', ''The Strategist'', ''Curbed'', and ''Grub Street''. The former ''Recode'' was integrated into ''Vox'', while ''Racked'' was shut down. Vox Media's brands are built on Concert, a marketplace for advertising, and Chorus, its Proprietary software, proprietary content manage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
