OpenLink Virtuoso SPARQL Query Editor RDF Views

How To Let Virtuoso Render Relational Data As RDF?

By default, Virtuoso stores all RDF data in a single "RDF Storage" that consists of one four-column relational table containing all triples of all graphs.

System Adminstrator can extend this basic schema with more storages and more groups of triples to represent variety of SQL tables and views stored in Virtuoso or in attached data sources.

Storage <http://www.openlinksw.com/schemas/virtrdf#DefaultQuadStorage>

This pre-defined storage is used by default by all SPARQL queries.

It contains 1 top-level quad maps ("RDF Views"):

  1. Top-level quad map ("RDF View") <http://www.openlinksw.com/schemas/virtrdf#SysUsers>
    The quad map provides triples for graph <http://www.iodbc.org/sys>.
    The data come from DB.DBA.SYS_USERS, DB.DBA.SYS_ROLE_GRANTS

The storage has a default quad map <http://www.openlinksw.com/schemas/virtrdf#DefaultQuadMap>
The quad map provides triples for various graphs named by format <http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank>.
The data come from DB.DBA.RDF_QUAD

Storage <http://www.openlinksw.com/schemas/virtrdf#DefaultServiceStorage>

This pre-defined storage is used internally for SERVICE {...} clauses of SPARQL queries; not for regular use.

The storage contains no RDF Views.

The storage has a default quad map <http://www.openlinksw.com/schemas/virtrdf#DefaultServiceMap>
The quad map provides triples for various graphs named by format <http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank>.
The data come from system procedure views that compose and send HTTP requests to remote SPARQL service endpoints and then parse answers

Storage <http://www.openlinksw.com/schemas/virtrdf#IRI_Rank_Storage>

This storage is created by some application or by system administrator. It contains 1 top-level quad maps ("RDF Views"):

  1. Top-level quad map ("RDF View") <http://www.openlinksw.com/schemas/virtrdf#IRI_Rank_c_qm>
    The quad map provides triples for graph <http://www.openlinksw.com/schemas/virtrdf#IRI_Rank_c>.
    The data come from DB.DBA.RDF_IRI_RANK_C

The storage has a default quad map <http://www.openlinksw.com/schemas/virtrdf#DefaultQuadMap>
The quad map provides triples for various graphs named by format <http://www.openlinksw.com/virtrdf-data-formats#default-iid-nonblank>.
The data come from DB.DBA.RDF_QUAD

Storage <http://www.openlinksw.com/schemas/virtrdf#SyncToQuads>

This pre-defined storage is to enumerate quad maps mentioned by triggers based on RDF Views; these triggers track changes in source tables of RDF Views and materialize updated content of views as "physical" triples.

The storage contains no RDF Views.

The storage has no default quad map.