Yes, the Network Data Model (NDM) functionality of Oracle Spatial supports graph traversal functions. To use that functionality, the RDF graph has to be viewed as an NDM graph, and the following SQL can be used to do so. Essentially the NODE$ and LINK$ views are created, which are the entities that form an NDM graph. Once you have these views, the NDM Java API can be used to traverse the graph. More details on the NDM Java API can be found in the NDM documentation (Oracle® Spatial Topology and Network Data Models
10g Release 2 (10.2))

In the sample SQL below, the RDF model name is 'Nature'.

Melli

-- Example SQL for Creating NODE$ and LINK$ views, inserting metadata, and validating network --

CREATE VIEW nature_node$ AS
SELECT DISTINCT(a.start_node_id) node_id, b.value_name.getURL() node_name, a.active
FROM mdsys.rdfm_nature a, mdsys.rdf_value$ b
WHERE a.start_node_id=b.value_id
UNION
SELECT DISTINCT(c.canon_end_node_id) node_id, d.value_name.getURL() node_name, c.active
FROM mdsys.rdfm_nature c, mdsys.rdf_value$ d
WHERE c.canon_end_node_id=d.value_id ;

CREATE VIEW nature_link$ AS
SELECT a.link_id, b.value_name.getURL() link_name, a.start_node_id, a.canon_end_node_id end_node_id, a.active
FROM mdsys.rdfm_nature a, mdsys.rdf_value$ b
WHERE a.p_value_id=b.value_id ;

INSERT INTO user_sdo_network_metadata(network, network_category, node_table_name, link_table_name, link_direction)
VALUES( 'NATURE', 'LOGICAL','NATURE_NODE$', 'NATURE_LINK$', 'DIRECTED');
COMMIT;

SELECT sdo_net.validate_network('NATURE') FROM DUAL;