A triplestore or RDF store is a purpose-built
database
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases s ...
for the storage and retrieval of
triple
Triple is used in several contexts to mean "threefold" or a " treble":
Sports
* Triple (baseball), a three-base hit
* A basketball three-point field goal
* A figure skating jump with three rotations
* In bowling terms, three strikes in a row
* ...
s through
semantic queries. A triple is a data entity composed of subject–
predicate
Predicate or predication may refer to:
* Predicate (grammar), in linguistics
* Predication (philosophy)
* several closely related uses in mathematics and formal logic:
**Predicate (mathematical logic)
**Propositional function
**Finitary relation, o ...
–object, like "Bob is 35" or "Bob knows Fred".
Much like a
relational database, information in a triplestore is stored and retrieved via a
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 language ...
. Unlike a relational database, a triplestore is optimized for the storage and retrieval of triples. In addition to queries, triples can usually be imported and exported using
Resource Description Framework (RDF) and other formats.
Implementations
Some triplestores have been built as database engines from scratch, while others have been built on top of existing commercial relational database engines (such as SQL-based) or NoSQL
document-oriented database
A document-oriented database, or document store, is a computer program and data storage system designed for storing, retrieving and managing document-oriented information, also known as semi-structured data.
Document-oriented databases are one ...
engines. Like the early development of
online analytical processing
Online analytical processing, or OLAP (), is an approach to answer multi-dimensional analytical (MDA) queries swiftly in computing. OLAP is part of the broader category of business intelligence, which also encompasses relational databases, repor ...
(OLAP) databases, this intermediate approach allowed large and powerful database engines to be constructed for little programming effort in the initial phases of triplestore development. It seems likely that native triplestores will have the advantage for performance over a longer period of time. A difficulty with implementing triplestores over SQL is that although "triples" may thus be "stored", implementing efficient querying of a graph-based RDF model (such as mapping from
SPARQL
SPARQL (pronounced " sparkle" , a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language—that is, a semantic query language for databases—able to retrieve and manipulate data stored in Resource Description ...
) onto SQL queries is difficult.
Related database types
Adding a name to the triple makes a "quad store" or
named graph.
A
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 rel ...
has a more generalized structure than a triplestore, using graph structures with nodes, edges, and properties to represent and store data. Graph databases might provide index-free adjacency, meaning every element contains a direct pointer to its adjacent elements, and no index lookups are necessary. General graph databases that can store any graph are distinct from specialized graph databases such as triplestores and network databases.
See also
*
Dataspaces
*
Entity–relationship model
An entity–relationship model (or ER model) describes interrelated things of interest in a specific domain of knowledge. A basic ER model is composed of entity types (which classify the things of interest) and specifies relationships that can ex ...
* – The first two elements of the ''class-attribute-value'' triple (class, attribute) are pieces of some structural metadata having a defined semantic. The third element is a value, preferably from some controlled vocabulary.
*
Outline of databases
The following is provided as an overview of and topical guide to databases:
Database – organized collection of data, today typically in digital form. The data are typically organized to model relevant aspects of reality (for example, the av ...
*
Semantic Integration
Semantic integration is the process of interrelating information from diverse sources, for example calendars and to do lists, email archives, presence information (physical, psychological, and social), documents of all sorts, contacts (including ...
*
Semantic MediaWiki
Semantic MediaWiki (SMW) is an extension to MediaWiki that allows for annotating semantic data within wiki pages, thus turning a wiki that incorporates the extension into a semantic wiki. Data that has been encoded can be used in semantic search ...
— an example of subject-predicate-object support for
wikis
A wiki ( ) is an online hypertext publication collaboratively edited and managed by its own audience, using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project, and could be either open to the pub ...
, advanced query support, and implementations by many large organizations
*
SPARQL
SPARQL (pronounced " sparkle" , a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language—that is, a semantic query language for databases—able to retrieve and manipulate data stored in Resource Description ...
– W3C specification involving subject-predicate-object triples
**
List of SPARQL implementations
This list shows notable triplestores, APIs, and other storages that have implemented the W3C SPARQL standard.
* Amazon Neptune
* Apache Marmotta
* AllegroGraph
* Eclipse RDF4J
* Apache Jena with ARQ
* Blazegraph
* Cray Urika-GD
* IBM Db2 - Removed ...
*
Entity–attribute–value model
Entity–attribute–value model (EAV) is a data model to encode, in a space-efficient manner, entities where the number of attributes (properties, parameters) that can be used to describe them is potentially vast, but the number that will actuall ...
is a similar approach to data modeling.
References
External links
A list of large triplestoresLehigh University Benchmark (LUBM)How RDF Databases Differ from Other NoSQL SolutionsW3C SPARQL Working Groupwas RDF Data Access Working Group
SPARQL Query languageSPARQL ProtocolSPARQL 1.1 UpdateW3C Recommendation 21 March 2013
{{Use dmy dates, date=March 2017
Types of databases
Database management systems
Database theory
Metadata
Semantic Web