SPARQL-2 Flashcards
(12 cards)
What is the basic structure of a SPARQL SELECT query?
PREFIX declarations; SELECT ?vars WHERE { triple patterns }.
What is a triple pattern in SPARQL?
A graph pattern with subject, predicate, object (IRIs, literals, or variables) to match triples.
What is a SPARQL binding?
A mapping of query variables to RDF terms for each match solution.
What does the FILTER clause do in SPARQL?
Restricts solution mappings by a boolean expression or regex applied to variable bindings.
What does the UNION clause do in SPARQL?
Performs a logical OR between two pattern groups, matching solutions satisfying either group.
What does the OPTIONAL clause do in SPARQL?
Left-outer-joins solutions with an optional pattern, returning bindings even when the optional part fails.
What is the SPARQL aggregation extension?
Adds aggregate functions (COUNT, SUM, MIN, MAX, AVG, GROUP_CONCAT) and GROUP BY to summarize results.
What is the SPARQL subqueries extension?
Allows nesting SELECT queries inside WHERE clauses to compute intermediate result sets.
What is the SPARQL property paths extension?
Enables matching paths of arbitrary length or specific patterns using operators like |, /, *, +, ^.
What is the SPARQL UPDATE extension?
Provides operations for modifying RDF data (INSERT, DELETE, LOAD, CLEAR, CREATE, etc.).
What is the SPARQL federation extension?
Enables querying remote SPARQL endpoints within a query using the SERVICE keyword.
What is the SPARQL entailment regimes extension?
Defines inference regimes (RDF, RDFS, OWL) that add inferred triples during query evaluation.
