Hugh Darwen | |
|---|---|
 | |
| Born | 1943 (age 81–82) |
| Nationality | British |
| Occupation(s) | author, lecturer, researcher, and consultant, specializing in relational database theory |
| Employer | (until 2004) IBM |
| Known for | Relational database theory |
Hugh Darwen is a computer scientist who was an employee of IBM United Kingdom from 1967 [1] to 2004, and has been involved in the development of the relational model. [2]
From 1978 to 1982 he was a chief architect on Business System 12, a database management system that faithfully embraced the principles of the relational model. [3] He worked closely with Christopher J. Date and represented IBM at the ISO SQL committees (JTC1 SC32 WG3 Database languages, [4] WG4 SQL/MM [5] ) until his retirement from IBM. Darwen is the author of The Askew Wall [6] and co-author of The Third Manifesto, a proposal for serving object-oriented programs with purely relational databases without compromising either side and getting the best of both worlds, arguably even better than with so-called object-oriented databases. [7]
From 2004 to 2013 he lectured on relational databases at the Department of Computer Science, University of Warwick (UK), [8] and from 1989 to 2014 was a tutor and consultant for the Open University (UK) [9] where he was awarded a MUniv honorary degree for academic and scholarly distinction. [10] He was also awarded a DTech (Doctor in Technology) honorary degree by the University of Wolverhampton. [11] He later taught a database language designed by Chris Date and himself called Tutorial D, [12] part of a proposed family of database query languages called "D". [13]
He has written two books on the card game bridge, both on the subject of double dummy problems, on which he has a website. Alan Truscott has called him "the world's leading authority" on composed bridge problems. [14] He was responsible for the double dummy column in Bridge Magazine and other UK bridge publications from 1965 to 2004.
His early works were published under the pseudonym of Andrew Warden: both names are anagrams of his surname.[ clarification needed ]
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.
Database normalization is the process of structuring a relational database 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.
Martin Fowler is a British software developer, author and international public speaker on software development, specialising in object-oriented analysis and design, UML, patterns, and agile software development methodologies, including extreme programming.
A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970.
The relational model (RM) is an approach to managing data using a structure and language consistent with first-order predicate logic, first described in 1969 by English computer scientist Edgar F. Codd, where all data are represented in terms of tuples, grouped into relations. A database organized in terms of the relational model is a relational database.
Structured Query Language (SQL) is a domain-specific language used to manage data, especially in a relational database management system (RDBMS). It is particularly useful in handling structured data, i.e., data incorporating relations among entities and variables.
An object–relational database (ORD), or object–relational database management system (ORDBMS), is a database management system (DBMS) similar to a relational database, but with an object-oriented database model: objects, classes and inheritance are directly supported in database schemas and in the query language. Also, as with pure relational systems, it supports extension of the data model with custom data types and methods.
Fabian Pascal is a Romanian-American consultant to large software vendors such as IBM, Oracle Corporation, and Borland, but is better known as an author and seminar speaker. Born in Romania, Pascal lives in the San Francisco, CA area of the US, and works in association with Christopher J. Date.
Chris John Date is an independent author, lecturer, researcher, and consultant, specializing in relational database theory.
Edgar Frank "Ted" Codd was a British computer scientist who, while working for IBM, invented the relational model for database management, the theoretical basis for relational databases and relational database management systems. He made other valuable contributions to computer science, but the relational model, a very influential general theory of data management, remains his most mentioned, analyzed and celebrated achievement.
First normal form (1NF) is a property of a relation in a relational database. A relation is in first normal form if and only if no attribute domain has relations as elements. Or more informally, that no table column can have tables as values. Database normalization is the process of representing a database in terms of relations in standard normal forms, where first normal is a minimal requirement. SQL-92 does not support creating or using table-valued columns, which means that using only the "traditional relational database features" most relational databases will be in first normal form by necessity. Database systems which do not require first normal form are often called NoSQL systems. Newer SQL standards like SQL:1999 have started to allow so called non-atomic types, which include composite types. Even newer versions like SQL:2016 allow JSON.
Dataphor is an open-source truly-relational database management system (RDBMS) and its accompanying user interface technologies, which together are designed to provide highly declarative software application development. The Dataphor Server has its own storage engine or it can be a virtual, or federated, DBMS, meaning that it can utilize other database engines for storage.
An XML database is a data persistence software system that allows data to be specified, and stored, in XML format. This data can be queried, transformed, exported and returned to a calling system. XML databases are a flavor of document-oriented databases which are in turn a category of NoSQL database.
In relational databases, relvar is a term introduced by C. J. Date and Hugh Darwen as an abbreviation for relation variable in their 1995 paper The Third Manifesto, to avoid the confusion sometimes arising from the use of the term "relation", by the inventor of the relational model, E. F. Codd, for a variable to which a relation is assigned as well as for the relation itself. The term is used in Date's well-known database textbook An Introduction to Database Systems and in various other books authored or coauthored by him.
In SQL, null or NULL is a special marker used to indicate that a data value does not exist in the database. Introduced by the creator of the relational database model, E. F. Codd, SQL null serves to fulfill the requirement that all true relational database management systems (RDBMS) support a representation of "missing information and inapplicable information". Codd also introduced the use of the lowercase Greek omega (ω) symbol to represent null in database theory. In SQL, NULL is a reserved word used to identify this marker.
Object–relational impedance mismatch is a set of difficulties going between data in relational data stores and data in domain-driven object models. Relational Database Management Systems (RDBMS) is the standard method for storing data in a dedicated database, while object-oriented (OO) programming is the default method for business-centric design in programming languages. The problem lies in neither relational databases nor OO programming, but in the conceptual difficulty mapping between the two logic models. Both logical models are differently implementable using database servers, programming languages, design patterns, or other technologies. Issues range from application to enterprise scale, whenever stored relational data is used in domain-driven object models, and vice versa. Object-oriented data stores can trade this problem for other implementation difficulties.
Sixth normal form (6NF) is a normal form used in relational database normalization which extends the relational algebra and generalizes relational operators to support interval data, which can be useful in temporal databases.
David McGoveran is an American computer scientist and physicist, software industry analyst, and inventor. In computer science, he is recognized as one of the pioneers of relational database theory.
Nikos Lorentzos is a Greek professor of Informatics. He is a specialist on the Relational Model of Database Management, having made contributions in the field of temporal databases, where he has co-authored a book with Hugh Darwen and Christopher J Date.
NoSQL is an approach to database design that focuses on providing a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Instead of the typical tabular structure of a relational database, NoSQL databases house data within one data structure. Since this non-relational database design does not require a schema, it offers rapid scalability to manage large and typically unstructured data sets. NoSQL systems are also sometimes called "Not only SQL" to emphasize that they may support SQL-like query languages or sit alongside SQL databases in polyglot-persistent architectures.
{{citation}}: CS1 maint: numeric names: authors list (link).The relational model was originally conceived by Dr. Edgar F. Codd and subsequently maintained and developed by Hugh Darwen and Chris Date as a general model of data[ permanent dead link ]
at University of Warwick