|
The network model is a database model conceived as a flexible way of representing objects and their relationships. Its original inventor was Charles Bachman, and it was developed into a standard specification published in 1969 by the CODASYL Consortium. Where the hierarchical model structures data as a tree of records, with each record having one parent record and many children, the network model allows each record to have multiple parent and child records, forming a lattice structure. A database model is a theory or specification describing how a database is structured and used. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
The relational model for database management is a data model based on predicate logic and set theory. ...
An object-relational database (ORD) or object-relational database management system (ORDBMS) is a relational database management system that allows developers to integrate the database with their own custom data types and methods. ...
In an object oriented database, information is represented in the form of objects like in object oriented programming. ...
The Associative Model of Data is a data model which, it is claimed, offers numerous advantages over the current industry-leading relational database technology used in the largest percentage of modern database systems. ...
The concept-oriented data model is a data model based on lattice theory and ordered sets. ...
Multidimensional databases are variously (depending on the context) data aggregators which combine data from a multitude of data sources; databases which offer networks, hierarchies, arrays and other data formats difficult to model in SQL; or databases which offer a high degree of flexibility in the definition of dimensions, units, and...
The star schema (sometimes referenced as star join schema) is the simplest data warehouse schema, consisting of a single fact table with a compound primary key, with one segment for each dimension and with additional columns of additive, numeric facts. ...
A database model is a theory or specification describing how a database is structured and used. ...
Charles W. Bachman is a prominent computer scientist, particularly in the area of databases. ...
1969 (MCMLXIX) was a common year starting on Wednesday (the link is to a full 1969 calendar). ...
CODASYL (often spelt Codasyl) is an acronym for COnference on DAta SYstems Languages. This was a IT industry consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers. ...
In computer science, a tree is a widely-used computer data structure that emulates a tree structure with a set of linked nodes. ...
The name lattice is suggested by the form of the Hasse diagram depicting it. ...
The chief argument in favour of the network model, in comparison to the hierarchic model, was that it allowed a more natural modeling of relationships between entities. Although the model was widely implemented and used, it failed to become dominant for two main reasons. Firstly, IBM chose to stick to the hierarchical model in their established products such as IMS and DL/I. Secondly, it was eventually displaced by the relational model, which offered a higher-level, more declarative interface. Until the early 1980s the performance benefits of the low-level navigational interfaces offered by hierarchical and network databases were persuasive for many large-scale applications, but as hardware became faster, the extra productivity and flexibility of relational systems pushed the network model out of the enterprise database world. To meet Wikipedias quality standards, this article or section may require cleanup. ...
Information Management System (IMS) is a joint hierarchical database and information management system. ...
The relational model for database management is a data model based on predicate logic and set theory. ...
Unlike the relational model, however, which relies on a closed world (such as a centrally-managed database), the network model works well in an open world, making it useful for operating on wider-scale, unreliable, distributed data enabled by the Internet and World Wide Web. The closed world assumption is the presumption that what is not currently known to be true is false. ...
The open world assumption is the presumption that what is not stated is currently unknown. ...
WWWs historical logo designed by Robert Cailliau The World Wide Web (WWW or simply the Web) is a global, read-write information space. ...
History In 1969, the Conference on Data Systems Languages (CODASYL) established the first specification of the network database model. This was followed by a second publication in 1971, which became the basis for most implementations. Subsequent work continued into the early 1980s, culminating in an ISO specification, but this had little influence on products. 1969 (MCMLXIX) was a common year starting on Wednesday (the link is to a full 1969 calendar). ...
CODASYL (often spelt Codasyl) is an acronym for COnference on DAta SYstems Languages. This was a IT industry consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers. ...
1971 (MCMLXXI) was a common year starting on Friday (the link is to a full 1971 calendar). ...
The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from national standards bodies. ...
See also CODASYL (often spelt Codasyl) is an acronym for COnference on DAta SYstems Languages. This was a IT industry consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers. ...
Navigational databases incorporate both the network model and hierarchical model of database interfaces. ...
References - Charles W. Bachman, The Programmer as Navigator. ACM Turing Award lecture, Communications of the ACM, Volume 16, Issue 11, 1973, pp. 653-658, ISSN 0001-0782, DOI:10.1145/355611.362534
The A.M. Turing Award is given annually by the Association for Computing Machinery to a person selected for contributions of a technical nature made to the computing community. ...
ISSN, or International Standard Serial Number, is the unique eight-digit number applied to a periodical publication including electronic serials. ...
A digital object identifier (or DOI) is a permanent identifier (permalink) given to a World Wide Web file or other Internet document so that if its Internet address changes, users will be redirected to its new address. ...
External links - Network (CODASYL) Data Model
|
Feeds |
Contact