Daplex

Last updated

Daplex is a computer language introduced in 1981 by David Shipman of the Computer Corporation of America. [1] Daplex was designed for creating distributed database systems and can be used as a global query language. [2]

Contents

Example of Daplex Local Schemata

Type EMPLOYEE is entity Name: string SSN: integer ADDRESS: string SALARY: Float end entity;

Related Research Articles

Database Organized collection of data

A database is an organized collection of data, generally stored and accessed electronically from a computer system. Where databases are more complex they are often developed using formal design and modeling techniques.

A relational database is a digital database based on the relational model of data, as proposed by E. F. Codd in 1970. A software system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems have an option of using the SQL for querying and maintaining the database.

SQL is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS). It is particularly useful in handling structured data, i.e. data incorporating relations among entities and variables.

Object-relational mapping in computer science is a programming technique for converting data between incompatible type systems using object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language. There are both free and commercial packages available that perform object-relational mapping, although some programmers opt to construct their own ORM tools.

Data model An abstract model that organizes elements of data and standardizes how they relate to on another and to real world entities.

A data model is an abstract model that organizes elements of data and standardizes how they relate to one another and to the properties of real-world entities. For instance, a data model may specify that the data element representing a car be composed of a number of other elements which, in turn, represent the color and size of the car and define its owner.

Computer science is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. One well known subject classification system for computer science is the ACM Computing Classification System devised by the Association for Computing Machinery.

A data dictionary, or metadata repository, as defined in the IBM Dictionary of Computing, is a "centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format". Oracle defines it as a collection of tables with metadata. The term can have one of several closely related meanings pertaining to databases and database management systems (DBMS):

Entity–relationship model Model or diagram describing interrelated things

An entity–relationship model describes interrelated things of interest in a specific domain of knowledge. A basic ER model is composed of entity types and specifies relationships that can exist between entities.

A database server is a server which uses a database application that provides database services to other computer programs or to computers, as defined by the client–server model. Database management systems (DBMSs) frequently provide database-server functionality, and some database management systems rely exclusively on the client–server model for database access.

An attribute–value pair, also called a name–value pair, key–value pair, or field–value pair, is a fundamental data representation in computing systems and applications. Designers often desire an open-ended data structure that allows for future extension without modifying existing code or data. In such situations, all or part of the data model may be expressed as a collection of 2-tuples in the form <attribute name, value> with each element being an attribute–value pair. Depending on the particular application and the implementation chosen by programmers, attribute names may or may not be unique.

The object–relational impedance mismatch is a set of conceptual and technical difficulties that are often encountered when a relational database management system (RDBMS) is being served by an application program written in an object-oriented programming language or style, particularly because objects or class definitions must be mapped to database tables defined by a relational schema.

Data integration involves combining data residing in different sources and providing users with a unified view of them. This process becomes significant in a variety of situations, which include both commercial and scientific domains. Data integration appears with increasing frequency as the volume and the need to share existing data explodes. It has become the focus of extensive theoretical work, and numerous open problems remain unsolved. Data integration encourages collaboration between internal as well as external users. The data being integrated must be received from a heterogeneous database system and transformed to a single coherent data store that provides synchronous data across a network of files for clients. A common use of data integration is in data mining when analyzing and extracting information from existing databases that can be useful for Business information.

Entity–attribute–value model (EAV) is a data model to encode, in a space-efficient manner, entities where the number of attributes that can be used to describe them is potentially vast, but the number that will actually apply to a given entity is relatively modest. Such entities correspond to the mathematical notion of a sparse matrix.

In computing, an attribute is a specification that defines a property of an object, element, or file. It may also refer to or set the specific value for a given instance of such. For clarity, attributes should more correctly be considered metadata. An attribute is frequently and generally a property of a property. However, in actual usage, the term attribute can and is often treated as equivalent to a property depending on the technology being discussed. An attribute of an object usually consists of a name and a value; of an element, a type or class name; of a file, a name and extension.

Entity Framework (EF) is an open source object-relational mapping (ORM) framework for ADO.NET. It was originally shipped as an integral part of .NET Framework. Starting with Entity Framework version 6, it has been delivered separately from the .NET Framework.

Victor M. Markowitz is Chief Informatics Officer & Associate Director at DOE Joint Genome Institute (JGI), and head of Lawrence Berkeley National Laboratory's Biological Data Management and Technology Center.

The following is provided as an overview of and topical guide to databases:

Cypher is a declarative graph query language that allows for expressive and efficient data querying in a property graph.

A semantic triple, or RDF triple or simply triple, is the atomic data entity in the Resource Description Framework (RDF) data model. As its name indicates, a triple is a set of three entities that codifies a statement about semantic data in the form of subject–predicate–object expressions.

Grakn is an open-source, distributed knowledge graph database for knowledge-oriented systems. It is an evolution of the relational database for highly interconnected data as it provides a concept-level schema that fully implements the Entity-Relationship (ER) model. However, Grakn’s schema is a type system that implements the principles of knowledge representation and reasoning. This enables Grakn's declarative query language, Graql, to provide a more expressive modelling language and the ability to perform deductive reasoning over large amounts of complex data. Effectively, Grakn is a knowledge base for artificial intelligence and cognitive computing systems.

References

  1. Rose, Elisabeth (Summer 1991). "Data Modeling for Non-Standard Data". Journal of Database Management. 2 (3): 10. ISSN   1063-8016.
  2. Prabhu, C.S.R. (1992). "3.7 Daplex". Semantic Database Systems: A Functional Introduction. Universities Press (India) Private Limited. pp. 60–71. ISBN   0-86311-346-X.