Tracker SPARQL Library Reference Manual: Tracker SPARQL Library Reference Manual

This is a documentation preview for the next version of Tracker, generated from tracker.git commit c585703.

See the Tracker website for more documentation.

for libtracker-sparql "3.1.0.beta" . The latest version of this documentation can be found on-line at https://developer.gnome.org/libtracker-sparql/stable .

I. Overview

Connection methods
Connecting from Flatpak

II. Reference

TrackerResource — Represents a single Tracker resource
TrackerNamespaceManager — A set of well-known namespaces, and known abbreviations for them
TrackerSparqlConnection — Connection to SPARQL triple store
TrackerSparqlStatement — Prepared statements
TrackerSparqlCursor — Iteration of the query results
TrackerNotifier — Listen to changes in the Tracker database
TrackerEndpoint — Expose a database outside the process
TrackerBatch — Update batches
Utility Functions — miscellaneous functionality
Version Information — variables and functions to check Tracker version
TrackerSparqlError — Error codes

III. Base ontology

Dublin Core metadata (DC) — Common superproperties for documents
XML schema (XSD) — Basic types definitions (int, double,...)
Resource Description Framework (RDF) — Core RDF classes to keep the internal consistency of the ontology
Nepomuk Resource Language (NRL) — Properties describing the ontologies.

IV. Defining ontologies

Creating an ontology

Defining a namespace
Defining classes
Defining properties
Defining cardinality of properties
Defining uniqueness
Defining indexes
Defining full-text search properties
Predefined elements

Accompanying metadata

Updating an ontology

V. Examples

Querying the Store
Updating the Store
Updating the Store with Blank Nodes

VI. Implementation limits

VII. Performance dos and donts

Avoid queries with unrestricted predicates
Avoid the negated property path
Specify graphs wherever possible
Avoid substring matching
Use TrackerSparqlStatement

VIII. SPARQL as understood by Tracker

The default graph
Blank nodes
Property functions
Syntax extensions
Mapping IDs and IRIs
Parameters and prepared statements
Full-text search

IX. Builtin SPARQL functions

String functions
DateTime functions
Full-text search functions
URI functions
Geolocation functions
Identification functions

Migrating from libtracker-sparql 1.x to 2.0

Stricter SPARQL1.1
No getters for direct/bus SPARQL connections
TrackerSparqlBuilder is deprecated

Migrating from libtracker-sparql 2.x to 3.0

Graph semantics
No libtracker-control
No libtracker-miner
No tracker_sparql_connection_load()/load_async()/load_finish()
No tracker_sparql_connection_statistics()/statistics_async()/statistics_finish()
No TRACKER_NOTIFIER_FLAG_NOTIFY_UNEXTRACTED
No TRACKER_NOTIFIER_FLAG_QUERY_LOCATION
No tracker_notifier_new()
Different signature of TrackerNotifier::events signal
Return value change in tracker_sparql_connection_update_array()
No tracker_sparql_connection_get()/get_async()
No tracker_sparql_connection_set_domain
No priority argument on SPARQL updates

X. SPARQL tutorial

RDF Triples
SPARQL

Annotation Glossary