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Relational database. A relational database ( RDB[ 1]) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. [ 2] A database management system used to maintain relational databases is a relational database management system ( RDBMS ). Many relational database systems are equipped with the option of using SQL ...
QUEL is a relational database query language, based on tuple relational calculus, with some similarities to SQL. It was created as a part of the Ingres DBMS effort at University of California, Berkeley, based on Codd 's earlier suggested but not implemented Data Sub-Language ALPHA. QUEL was used for a short time in most products based on the ...
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. [ 1] 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 ...
In computing, online analytical processing, or OLAP ( / ˈoʊlæp / ), is an approach to quickly answer multi-dimensional analytical (MDA) queries. [ 1] The term OLAP was created as a slight modification of the traditional database term online transaction processing (OLTP). [ 2] OLAP is part of the broader category of business intelligence ...
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, [ 1][ 2] where all data is represented in terms of tuples, grouped into relations. A database organized in terms of the relational model is a ...
Database catalog. A database catalog of a database instance consists of metadata in which definitions of database objects such as base tables, views (virtual tables), synonyms, value ranges, indexes, users, and user groups are stored. [ 1][ 2] The SQL standard specifies a uniform means to access the catalog, called the INFORMATION_SCHEMA, but ...
Database normalization 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 ...
Query language. A query language, also known as data query language or database query language ( DQL ), is a computer language used to make queries in databases and information systems. In database systems, query languages rely on strict theory to retrieve information. [ 1] A well known example is the Structured Query Language (SQL).