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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
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. 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 ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Description Framework
The Resource Description Framework (RDF) is a method to describe and exchange graph data. It was originally designed as a data model for metadata by the World Wide Web Consortium (W3C). It provides a variety of syntax notations and formats, of which the most widely used is Turtle ( Terse RDF Triple Language). 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 from subject to object, representing a predicate, and (3) a node for the object. Each of these parts can be identified by a Uniform Resource Identifier (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, and the RDF 1.1 specification in 2014. SPARQL is a standard query ... [...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: * Software construction#Construction languages, Construction language – all forms of communication by which a human can Computer programming, 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 file#Configuration languages, Configuration language – a language used to write configuration files ** Programming language – a formal language designed to communicate instructions to a machine, particularly a computer ***Scripting language – a type of programming language which typically is interpreted at runtime rather than being compiled ** Query language – a language used to make Information retrieval, queries in databases and information systems ** Transformation language – designed to transform some input te ... [...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. ... [...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 database. 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 rele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GraphQL
GraphQL is a data query and manipulation language that allows specifying what data is to be retrieved (" declarative data fetching") or modified. A GraphQL server can process a client query using data from separate sources and present the results in a unified graph. The language is not tied to any specific database or storage engine. There are several open-source runtime engines for GraphQL. History Facebook started GraphQL development in 2012 and released a draft specification and reference implementation as open source in 2015. In 2018, GraphQL was moved to the newly established GraphQL Foundation, hosted by the non-profit Linux Foundation. On February 9, 2018, the GraphQL Schema Definition Language became part of the specification. Many popular public APIs adopted GraphQL as the default way to access them. These include public APIs of Facebook, GitHub, Yelp, Shopify, Google Directions API and many others. Design GraphQL supports reading, writing (mutating), ... [...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 the openCypher project 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 tho ... [...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 database. 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 nuclease 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 subst ... [...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] |
