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RDQL
An RDF query language is a computer language, specifically a query language for databases, able to retrieve and manipulate data stored in Resource Description Framework (RDF) format. SPARQL has emerged as the standard RDF query language, and in 2008 became a W3C recommendation. Query language properties Properties relevant to RDF query language design include support for the RDF format: * Support for RDF data, which is a collection of triples that form the RDF graph * Support for RDF semantics and inference that allows for entailment, the reasoning about the meaning of RDF graphs * Support for schema data types, such as XML schema and for desirable language features: * Expressiveness: the power of query expression that may be constructed * Closure: data operations on an RDF graph should result in another RDF graph * Orthogonality: data operations are independent of the context in which they are used * Safety: every expression returns a finite set of results. Query language ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Query Language
Query languages, data query languages or database query languages (DQL) are computer languages used to make queries in databases and information systems. A well known example is the Structured Query Language (SQL). Types Broadly, query languages can be classified according to whether they are database query languages or information retrieval query languages. The difference is that a database query language attempts to give factual answers to factual questions, while an information retrieval query language attempts to find documents containing information that is relevant to an area of inquiry. Other types of query languages include: * Full-text. The simplest query language is treating all terms as bag of words that are to be matched with the postings in the inverted index and where subsequently ranking models are applied to retrieve the most relevant documents. Only tokens are defined in the CFG. Web search engines often use this approach. * Boolean. A query language that also s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Description Framework
The Resource Description Framework (RDF) is a World Wide Web Consortium (W3C) standard originally designed as a data model for metadata. It has come to be used as a general method for description and exchange of graph data. RDF provides a variety of syntax notations and data serialization formats with Turtle (Terse RDF Triple Language) currently being the most widely used notation. RDF is a directed graph composed of triple statements. An RDF graph statement is represented by: 1) a node for the subject, 2) an arc that goes from a subject to an object for the predicate, and 3) a node for the object. Each of the three parts of the statement can be identified by a URI. An object can also be a literal value. This simple, flexible data model has a lot of expressive power to represent complex situations, relationships, and other things of interest, while also being appropriately abstract. RDF was adopted as a W3C recommendation in 1999. The RDF 1.0 specification was published in 2004, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Language
A computer language is a formal language used to communicate with a computer. Types of computer languages include: * Construction language – all forms of communication by which a human can specify an executable problem solution to a computer ** Command language – a language used to control the tasks of the computer itself, such as starting programs ** Configuration language – a language used to write configuration files ** Programming language – a formal language designed to communicate instructions to a machine, particularly a computer ** Query language – a language used to make queries in databases and information systems ** Transformation language – designed to transform some input text in a certain formal language into a modified output text that meets some specific goal * Data exchange language – a language that is domain-independent and can be used for data from any kind of discipline; examples: JSON, XML * Markup language &ndas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topic Maps
A topic map is a standard for the representation and interchange of knowledge, with an emphasis on the findability of information. Topic maps were originally developed in the late 1990s as a way to represent back-of-the-book index structures so that multiple indexes from different sources could be merged. However, the developers quickly realized that with a little additional generalization, they could create a meta-model with potentially far wider application. The ISO/IEC standard is formally known as ISO/IEC 13250:2003. A topic map represents information using * ''topics'', representing any concept, from people, countries, and organizations to software modules, individual files, and events, * ''associations'', representing hypergraph relationships between ''topics'', and * ''occurrences'', representing information resources relevant to a particular ''topic''. Topic maps are similar to concept maps and mind maps in many respects, though only topic maps are ISO standards. Topi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Database
A graph database (GDB) is a database that uses graph structures for semantic queries with nodes, edges, and properties to represent and store data. A key concept of the system is the ''graph'' (or ''edge'' or ''relationship''). The graph relates the data items in the store to a collection of nodes and edges, the edges representing the relationships between the nodes. The relationships allow data in the store to be linked together directly and, in many cases, retrieved with one operation. Graph databases hold the relationships between data as a priority. Querying relationships is fast because they are perpetually stored in the database. Relationships can be intuitively visualized using graph databases, making them useful for heavily inter-connected data. Graph databases are commonly referred to as a NoSQL. Graph databases are similar to 1970s network model databases in that both represent general graphs, but network-model databases operate at a lower level of abstraction and lac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gremlin (programming Language)
Gremlin is a graph traversal language and virtual machine developed by Apache TinkerPop of the Apache Software Foundation. Gremlin works for both OLTP-based graph databases as well as OLAP-based graph processors. Gremlin's automata and functional language foundation enable Gremlin to naturally support: imperative and declarative querying; host language agnosticism; user-defined domain specific languages; an extensible compiler/optimizer, single- and multi-machine execution models; hybrid depth- and breadth-first evaluation with Turing Completeness. As an explanatory analogy, Apache TinkerPop and Gremlin are to graph databases what the JDBC and SQL are to relational databases. Likewise, the Gremlin traversal machine is to graph computing as what the Java virtual machine is to general purpose computing. History * 2009-10-30 the project is born, and immediately named "TinkerPop" * 2009-12-25 v0.1 is the first release * 2011-05-21 v1.0 is released * 2012-05-24 v2.0 is released ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GraphQL
GraphQL is an open-source data query and manipulation language for APIs, and a runtime for fulfilling queries with existing data. GraphQL was developed internally by Facebook (now Meta) in 2012 before being publicly released in 2015. On 7 November 2018, the GraphQL project was moved from Facebook to the newly established GraphQL Foundation, hosted by the non-profit Linux Foundation. Since 2012, GraphQL's rise has closely followed the adoption timeline as set out by Lee Byron, GraphQL's creator. Byron's goal is to make GraphQL omnipresent across web platforms. GraphQL provides an approach to developing web APIs and has been compared and contrasted with REST and other web service architectures. It allows clients to define the structure of the data required, and the same structure of the data is returned from the server. This prevents excessively large amounts of data from being returned, but can impede web caching of query results. The flexibility and richness of the query lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cypher Query Language
Cypher is a declarative graph query language that allows for expressive and efficient data querying in a property graph. Cypher was largely an invention of Andrés Taylor while working for Neo4j, Inc. (formerly Neo Technology) in 2011. Cypher was originally intended to be used with the graph database Neo4j, but was opened up through thopenCypherproject in October 2015. The language was designed with the power and capability of SQL (standard query language for the relational database model) in mind, but Cypher was based on the components and needs of a database built upon the concepts of graph theory. In a graph model, data is structured as nodes ( vertices in math and network science) and relationships (edges in math and network science) to focus on how entities in the data are connected and related to one another. Graph model Cypher is based on the Property Graph Model, which organizes data into nodes and edges (called “relationships” in Cypher). In addition to those st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Database
A graph database (GDB) is a database that uses graph structures for semantic queries with nodes, edges, and properties to represent and store data. A key concept of the system is the ''graph'' (or ''edge'' or ''relationship''). The graph relates the data items in the store to a collection of nodes and edges, the edges representing the relationships between the nodes. The relationships allow data in the store to be linked together directly and, in many cases, retrieved with one operation. Graph databases hold the relationships between data as a priority. Querying relationships is fast because they are perpetually stored in the database. Relationships can be intuitively visualized using graph databases, making them useful for heavily inter-connected data. Graph databases are commonly referred to as a NoSQL. Graph databases are similar to 1970s network model databases in that both represent general graphs, but network-model databases operate at a lower level of abstraction and lac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenine (programming Language)
Haystack is a project at the Massachusetts Institute of Technology to research and develop several applications around personal information management and the Semantic Web. The most notable of those applications is the Haystack client, a research personal information manager (PIM) and one of the first to be based on semantic desktop technologies. The Haystack client is published as open source software under the BSD license. Similar to the Chandler PIM, the Haystack system unifies handling different types of unstructured information. This information has a common representation in RDF that is presented to users in a configurable human-readable way. Adenine Haystack was developed in the RDF-aware dynamic language Adenine which was created for the project. The language was named after the nucleobase adenine and is a scripting language that is cross-platform. It is the perhaps the earliest example of a homoiconic general graph (rather than list/tree) programming language. A su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DAML+OIL
The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies. Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for various domains: the nouns representing classes of objects and the verbs representing relations between the objects. Ontologies resemble class hierarchies in object-oriented programming but there are several critical differences. Class hierarchies are meant to represent structures used in source code that evolve fairly slowly (perhaps with monthly revisions) whereas ontologies are meant to represent information on the Internet and are expected to be evolving almost constantly. Similarly, ontologies are typically far more flexible as they are meant to represent information on the Internet coming from all sorts of heterogeneous data sources. Class hierarchies on the other hand tend to be fairly static and rely on far less diverse and more structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
