Sesame

Sesame

Lightweight alternativa k Jeně, pouziva jej LDM. Všechno, co je potřeba vědět je tady:

• uživatelská dokumentace
• javadoc
• Virtuoso provider

Sesame pouziva jinou terminologii nez Jena (Quad -> Statement, NamedGraph -> context). Zatim to vypada, ze dotazovani by bylo v Sesame i rycheljsi, ale neumoznuje null ve vysledcich dotazu (afaik lze obejit pouze vypnutim assertions v Jave).

Pri pouziti equals() na Statement se neporovnava (verze 2.6.5) jmenny graf.

Querying

The Repository API has a number of methods for creating and evaluating queries. Three types of queries are distinguished: tuple queries, graph queries and boolean queries. The query types differ in the type of results that they produce.

The result of a tuple query is a set of tuples (or variable bindings), where each tuple represents a solution of a query. This type of query is commonly used to get specific values (URIs, blank nodes, literals) from the stored RDF data.

The result of graph queries is an RDF graph (or set of statements). This type of query is very useful for extracting sub-graphs from the stored RDF data, which can then be queried further, serialized to an RDF document, etc.

The result of boolean queries is a simple boolean value, i.e. true or false. This type of query can be used to check if a repository contains specific information.

• results of the queries can be processed in a pull-manner (by iterating over the results) or push-manner (by defining a callback method)
• lazy retrieving