|
ISBL
ISBL (Information Systems Base Language) is the relational algebra notation that was invented for PRTV, one of the earliest database management systems to implement E.F. Codd's relational model 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 t ... of data. Example OS = ORDERS * SUPPLIERS LIST OS: NAME="Brooks" % SNAME, ITEM, PRICE See also * IBM Business System 12 - An IBM industrial strength relational DBMS influenced by ISBL. It was developed for use by customers of IBM's time-sharing service bureaux in various countries in the early 1980s. External links Sample ISBL usage Query languages {{compu-sci-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Algebra
In database theory, relational algebra is a theory that uses algebraic structures for modeling data and defining queries on it with well founded semantics (computer science), semantics. The theory was introduced by Edgar F. Codd. The main application of relational algebra is to provide a theoretical foundation for relational databases, particularly query languages for such databases, chief among which is SQL. Relational databases store tabular data represented as relation (database), relations. Queries over relational databases often likewise return tabular data represented as relations. The main purpose of relational algebra is to define Operator (mathematics), operators that transform one or more input relations to an output relation. Given that these operators accept relations as input and produce relations as output, they can be combined and used to express complex queries that transform multiple input relations (whose data are stored in the database) into a single output rela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Business System 12
Business System 12, or simply BS12, was one of the first fully relational database management systems, designed and implemented by IBM's ''Bureau Service'' subsidiary at the company's international development centre in Uithoorn, Netherlands. Programming started in 1978 and the first version was delivered in 1982. It was never widely used and essentially disappeared soon after the division was shut down in 1985, possibly because IBM and other companies settled on SQL as the standard. BS12's lasting contribution to history was the use of a new query language based on ISBL, created at IBM's UK ''Scientific Centre''. Developers of the famous System R underway in the US at the same time were also consulted on certain matters concerning the engine, but the BS12 team rejected SQL unequivocally, being convinced that this apparently unsound and difficult-to-use language (which at that time was also relationally incomplete) would never catch on. BS12 included a number of interesting fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Peterlee Relational Test Vehicle (PRTV)
PRTV (''Peterlee Relational Test Vehicle'') was the world's first relational database management system that could handle significant data volumes. It was a relational query system with powerful query facilities, but very limited update facility and no simultaneous multiuser facility. PRTV was a successor from the very first relational implementation, IS1. Features PRTV included several firsts in the relational database area: * implemented relational optimizer * implemented cost-based relational optimizer * handle tables of 1,000 rows up to 10,000,000 rows * user-defined functions (UDFs) within an RDB (also a large suite of built-in functions such as trigonometric and statistical) * geographic information system based on an RDB (using UDFs such as point-in-polygon). PRTV was based on a relational algebra, Information Systems Base Language (ISBL) and followed the relational model very strictly. Even features such as user-defined functions were formalized within that model. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Management System
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 ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edgar F
Edgar is a commonly used masculine English given name, from an Anglo-Saxon name ''Edgar'' (composed of '' ead'' "rich, prosperous" and '' gar'' "spear"). Like most Anglo-Saxon names, it fell out of use by the Late Middle Ages; it was, however, revived in the 18th century, and was popularised by its use for a character in Sir Walter Scott's '' The Bride of Lammermoor'' (1819). The name was more common in the United States than elsewhere in the Anglosphere during the 19th century. It has been a particularly fashionable name in Latin American countries since the 20th century. People with the given name * Edgar the Peaceful (942–975), king of England * Edgar the Ætheling (c. 1051 – c. 1126), last member of the Anglo-Saxon royal house of England * Edgar of Scotland (1074–1107), king of Scotland * Edgar Alaffita (born 1996), Mexican footballer * Edgar Allan (other), multiple people * Edgar Allen (other), multiple people * Edgar Angara (1934–2018), F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Model
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. The purpose of the relational model is to provide a declarative method for specifying data and queries: users directly state what information the database contains and what information they want from it, and let the database management system software take care of describing data structures for storing the data and retrieval procedures for answering queries. Most relational databases use the SQL data definition and query language; these systems implement what can be regarded as an engineering approximation to the relational model. A '' table'' in a SQL database schema corresponds to a predicate variable; the contents of a tab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
