Berkeley DB is not a relational database.

Berkeley DB has an architecture notably simpler than that of other database systems like relational database management systems.

* Carbonado – An open source relational database access layer.

The normalized structure divides data into entities, which creates several tables in a relational database.

A normal relational database however, is not efficient for business intelligence reports where dimensional modelling is prevalent.

:: Most modern relational databases include active database features in the form of database trigger.

Despite not adhering to the relational model as described by Codd, it has become the most widely used database language.

Clearly separating the three levels was a major feature of the relational database model implementations that dominate 21st century databases.

In the design of a relational database, the process of organizing database relations to minimize redundancy is called normalization.

DBMSs can be categorized according to the database model ( s ) that they support, such as relational or XML, the type ( s ) of computer they support, such as a server cluster or a mobile phone, the query language ( s ) that access the database, such as SQL or XQuery, performance trade-offs, such as maximum scale or maximum speed or others.

In a relational database clustering the two respective relations " Items " and " Orders " results in saving the expensive execution of a Join operation between the two relations whenever such a join is needed in a query ( the join result is already ready in storage by the clustering, available to be utilized ).

DBMSs may use a variety of database models, such as the relational model or object model, to conveniently describe and support applications.

DBMSs can be categorized according to the database model ( s ) that they support, such as relational or XML, the type ( s ) of computer they support, such as a server cluster or a mobile phone, the query language ( s ) that access the database, such as SQL or XQuery, performance trade-offs, such as maximum scale or maximum speed or others.

Alternatively, and especially in connection with the relational model of database management, the relation between attributes drawn from a specified set of domains can be seen as being primary.

In some cases, denormalisation helps cover up the inefficiencies inherent in relational database software.

A relational normalised database imposes a heavy access load over physical storage of data even if it is well tuned for high performance.

Database normalization is the process of organizing the fields and tables of a relational database to minimize redundancy and dependency.

Informally, a relational database table is often described as " normalized " if it is in the Third Normal Form.

They also produced one notable business application, a relational database called Cornerstone.

A key field is a field or set of fields ( a key is then said to be a composite key ) of a database ( typically a relational database ) table which together form a unique identifier for a database record ( a table entry ).

Shunning is often used as a pejorative term to describe any organizationally mandated disassociation, and has acquired a connotation of abuse and relational aggression.

In 2002 the product was acquired by Progress Software, which continues to develop the technology, and has recently expanded its use beyond the object database market to target use as a database for real-time computing, specifically designed for RFID data management, and as a cache for relational databases.

Adabas D is a relational database management system owned by Software AG since 1994, when Software AG acquired SQL-Datenbanksysteme GmbH from Siemens Nixdorf AG.

Definitions of complexity often depend on the concept of a " system "— a set of parts or elements that have relationships among them differentiated from relationships with other elements outside the relational regime.

Results from an experiment by Davachi, Mitchell, and Wagner ( 2003 ) and numerous subsequent studies ( Davachi, 2006 ) show that activation in the hippocampus during encoding is related to a subject's ability to recall prior events or later relational memories.

The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links.

The vendors of relational databases have fought off competition from these newer models by extending the capabilities of their own products to support a wider variety of data types.

Some of these extensions to the relational model integrate concepts from technologies that pre-date the relational model.

Those non-relational databases are significantly different from the classic relational databases.

According to the relational interpretation of quantum mechanics, first proposed by Carlo Rovelli, observations such as those in the double-slit experiment result specifically from the interaction between the observer ( measuring device ) and the object being observed ( physically interacted with ), not any absolute property possessed by the object.

It has also been suggested that space and distance themselves are relational, and that an electron can appear to be in " two places at once " – for example, at both slits – because its spatial relations to particular points on the screen remain identical from both slit locations.

KSR refocused its efforts from the scientific to the commercial marketplace, with emphasis on parallel relational databases and OLTP operations.

RFT distinguishes itself from Skinner's work by identifying and defining a particular type of operant conditioning known as derived relational responding, a learning process that, to date, appears to occur only in humans possessing a capacity for language.

Ellison took inspiration from the 1970 paper written by Edgar F. Codd on relational database management systems ( RDBMS ) named " A Relational Model of Data for Large Shared Data Banks.

Object databases are different from relational databases and belongs together to the broader database management system.

* Secondary storage management: Unlike relational databases, the lower-level management considerations of the data are separated from the logical data definition for clarity in design, ease of programming in the accessing application, and separation of concerns in administration.

A relational database is a collection of data items organized as a set of formally described tables from which data can be accessed easily.

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.

However, SQL databases, including DB2, deviate from the relational model in many details ; Codd fiercely argued against deviations that compromise the original principles.

SQL, initially pushed as the standard language for relational databases, deviates from the relational model in several places.

The following deviations from the relational model have been noted in SQL.

The deviation from the relational model arises from the fact that the implementation of this ad hoc concept in SQL involves the use of three-valued logic, under which the comparison of NULL with itself does not yield true but instead yields the third truth value, unknown ; similarly the comparison NULL with something other than itself does not yield false but instead yields unknown.

Users ( or programs ) request data from a relational database by sending it a query that is written in a special language, usually a dialect of SQL.

* Microsoft SQL Server, a relational database server from Microsoft