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Title: Overview
{{ style.xml }}
Tracker is a light-weight RDF [triple store](https://en.wikipedia.org/wiki/Triplestore)
implementation, with a [SPARQL 1.1](https://en.wikipedia.org/wiki/SPARQL) interface.
Tracker is implemented as a library, and may be used to create private databases,
in addition to connecting to remote endpoints for
[federated queries](https://en.wikipedia.org/wiki/Federated_search) or creating such
public endpoints.
## Advantages
Tracker offers the following advantages over other traditional databases:
- It is based on open standards. [SPARQL](https://www.w3.org/TR/2013/REC-sparql11-overview-20130321/)
is a [W3C recommendation](https://www.w3.org/). So is the [RDF](https://www.w3.org/RDF/) data model
and the various file formats available for import/export ([Turtle](https://www.w3.org/TR/turtle/),
[Trig](https://www.w3.org/TR/trig/), [JSON-LD](https://www.w3.org/TR/json-ld11/)).
- Database format and schema updates are automatically managed. The user
just needs to write and update the [ontology](ontologies.html) defining
the structure of the contained data. Databases will be created and
implicitly updated to format changes without the need to write supporting code.
- It has versatile serialization capabilities. Tracker is able to export RDF data into the same
formats it can import and load into databases. It is possible to perform backups, data mirroring,
data synchronization…
- A complete set of CLI tools is included. Tracker databases are fully introspectable
and can be opened with no additional supporting files, the command line tools can do
anything the library could do, and a number of utilities is provided.
- Distributed data is a first class citizen. SPARQL has builtin capabilities to
operate in a distributed environment, which may make it desirable to manage data
that is naturally open to multiple users. Tracker may interoperate with other
SPARQL implementations.
The Tracker library is written in C, but may be used from a number of languages
through [GObject introspection](https://gi.readthedocs.io/en/latest/), including
Rust, Python, or Javascript (through [GJS](https://gjs.guide/)).
Tracker is designed to be small, fast, and scalable. It is also robust and
fully [ACID](https://en.wikipedia.org/wiki/ACID). There are ready-made
[examples](examples.html) on how the Tracker library is put to use.
## Dependencies
Tracker depends on the following libraries:
- **GLib**: General-purpose utility library. GLib provides many useful data types,
macros, type conversions, string utilities, file utilities, a main loop abstraction,
and so on. More information available on the
[GLib API documentation](https://developer.gnome.org/glib/stable/).
- **GObject**: A library that provides a type system, a collection of fundamental
types including an object type, and a signal system. More information available
on the [GObject API documentation](https://developer.gnome.org/gobject/stable/).
- **GIO**: A modern, easy-to-use VFS API including abstractions for files, drives,
volumes, stream I/O, as well as network programming and IPC though D-Bus. More
information available on the [GIO API documentation](https://developer.gnome.org/gio/stable/).
- **SQLite**: SQLite is a C-language library that implements a small, fast,
self-contained, high-reliability, full-featured, SQL database engine. SQLite
is the most used database engine in the world. More information available on the
[SQLite website](https://sqlite.org).
- **Soup**: libsoup is an HTTP and HTTP/2 client/server library for GNOME. It uses
GObjects and the GLib main loop to integrate well with GNOME applications. More
information available on the [Soup API documentation](https://libsoup.org/libsoup-3.0/index.html)
- **LibXML2**: Libxml2 is the XML C parser and toolkit developed for the GNOME project.
More information at the [libXML2 website](https://gitlab.gnome.org/GNOME/libxml2/-/wikis/home).
- **JSON-GLib**: JSON-GLib is a library providing serialization and deserialization
support for the JavaScript Object Notation (JSON) format. More information at
the [API documentation](https://gnome.pages.gitlab.gnome.org/json-glib/).
## Connection methods
It is possible to create private databases in local storage, or to connect to
remote HTTP or D-Bus SPARQL endpoints. See [class@Tracker.SparqlConnection]
and its different constructors for each of these methods.
<div class="docblock">
{{ images/connections-diagram.svg }}
</div>
It is also possible to create public SPARQL endpoints, see [class@Tracker.Endpoint]
and its subclasses. Tracker can interoperate with any other SPARQL endpoint over HTTP,
such as [Wikidata](https://www.wikidata.org/wiki/Wikidata:Main_Page) or
[DBpedia](https://wiki.dbpedia.org/about).
|
