Example Performing Sponging with Private Graphs Using get:private pragma

The following example demonstrates how private sponging using get:private pragma works for database with private graphs.

1. Create few users in alphabetical order:
   

   
   DB.DBA.USER_CREATE ('Anna', 'Anna');
   DB.DBA.USER_CREATE ('Brad', 'Brad');
   DB.DBA.USER_CREATE ('Carl', 'Carl');
   

   
   
2. Set to Anna, Brad and Carl SPARQL SELECT, UPDATE and SPONGE permissions:
   

   
   grant SPARQL_SELECT to "Anna";
   grant SPARQL_SELECT to "Brad";
   grant SPARQL_SELECT to "Carl";
   
   grant SPARQL_UPDATE to "Anna";
   grant SPARQL_UPDATE to "Brad";
   grant SPARQL_UPDATE to "Carl";
   
   grant SPARQL_SPONGE to "Anna";
   grant SPARQL_SPONGE to "Brad";
   grant SPARQL_SPONGE to "Carl";
   
   

   
   
3. Set specific privileges: Setup assuming 3 users: Anna, Brad and Carl where each of these individual users has read access to graphs:
   

   
   
   -- Close any public access to "private" graphs
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('nobody', 0, 1);
   
   -- Set Read Only for public on graphs not listed as "private".
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('nobody', 1);
   
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('Anna', 0, 1);
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('Brad', 0, 1);
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('Carl', 0, 1);
   
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('Anna', 1);
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('Brad', 1);
   DB.DBA.RDF_DEFAULT_USER_PERMS_SET ('Carl', 1);
   

   
   
4. Assuming the following four sorts of access that are specified by four bits of an integer "permission bit-mask", following plain old UNIX style:
   • Bit 1 permits read access.
   • Bit 2 permits write access via SPARUL and is basically useless without bit 1 set.
   • Bit 4 permits write access via "RDF Network Resource Fetch" methods and is basically useless without bits 1 and 2 set.
   • Bit 8 allows retrieval of the list of members of a graph group. An IRI can be used as a graph IRI and as a graph group IRI at the same time, so bit 8 can be freely combined with any of bits 1, 2 or 4.
   • In the statements from below should be considered:
     • "15 = 8+4+2+1 " -- i.e. combining all the four sorts of access FROM above
     • "9 = 8 + 1" -- i.e. read access + access to retrieve the list of members for a given graph group
       

       
       
       -- Create Graph Group for Anna and set privileges:
       DB.DBA.RDF_GRAPH_GROUP_CREATE ('urn:Anna:Sponged:Data', 1);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Anna:Sponged:Data', 'Anna', 15);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Anna:Sponged:Data', 'Brad', 9);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Anna:Sponged:Data', 'Carl', 9);
       
       -- Create Graph Group for Brad and set privileges:
       DB.DBA.RDF_GRAPH_GROUP_CREATE ('urn:Brad:Sponged:Data', 1);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Brad:Sponged:Data', 'Anna', 9);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Brad:Sponged:Data', 'Brad', 15);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Brad:Sponged:Data', 'Carl', 9);
       
       -- Create Graph Group for Carl and set privileges:
       DB.DBA.RDF_GRAPH_GROUP_CREATE ('urn:Carl:Sponged:Data', 1);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Carl:Sponged:Data', 'Anna', 9);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Carl:Sponged:Data', 'Brad', 9);
       DB.DBA.RDF_GRAPH_USER_PERMS_SET ('urn:Carl:Sponged:Data', 'Carl', 15);
       
       
       -- Set Anna's, Brad's and Carl's graphs by inserting them into the <b>virtrdf:PrivateGraphs</b> graph group:
       DB.DBA.RDF_GRAPH_GROUP_INS ('http://www.openlinksw.com/schemas/virtrdf#PrivateGraphs', 'http://anna-example.com/');
       DB.DBA.RDF_GRAPH_GROUP_INS ('http://www.openlinksw.com/schemas/virtrdf#PrivateGraphs', 'http://brad-example.com/');
       DB.DBA.RDF_GRAPH_GROUP_INS ('http://www.openlinksw.com/schemas/virtrdf#PrivateGraphs', 'http://carl-example.com/');
       

       
       
5. Examples with invalid graph group names:
   1. Example with Non-existing Graph Group:
      

      
      -- An error for non-existing Graph group <http://nosuch/> will be raised.
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <http://nosuch/>
        SELECT *
        FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   2. Example with "virtrdf:PrivateGraphs?" graph group which is reserved for system usage:
      

      
      -- An error for attempt to add a graph to special graph group <http://www.openlinksw.com/schemas/virtrdf#PrivateGraphs> will be raised.
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private virtrdf:PrivateGraphs
        SELECT * FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   3. Example with "virtrdf:rdf_repl_graph_group" graph group which is reserved for system usage:
      

      
      -- An error for attempt to add a graph to special graph group <http://www.openlinksw.com/schemas/virtrdf#rdf_repl_graph_group> will be raised.
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private virtrdf:rdf_repl_graph_group
        SELECT * FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
6. Examples to check Anna's sponging permissions on different graph groups:
   1. Example for adding graph to Anna's graph group <urn:Anna:Sponged:Data>:
      

      
      -- No error will be raised as Anna has the efficient rights for graph group <urn:Anna:Sponged:Data>
      
      reconnect "Anna";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Anna:Sponged:Data>
        SELECT *
        FROM <http://anna-example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   2. Example for adding graph to Brad's graph group <urn:Brad:Sponged:Data>:
      

      
      -- An error will be rased because "Anna" has not enough rights on that group
      
      reconnect "Anna";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Brad:Sponged:Data>
        SELECT * FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   3. Example for adding graph to Carl's graph group <urn:Carl:Sponged:Data>:
      

      
      -- An error will be rased because "Anna" has not enough rights on that group
      
      reconnect "Anna";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Carl:Sponged:Data>
        SELECT *
        FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
7. Examples check Brad's sponging permissions on different graph groups:
   1. Example for adding graph to Anna's graph group <urn:Anna:Sponged:Data>:
      

      
      -- An error will be rased because "Brad" has not enough rights on that group
      
      reconnect "Brad";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Anna:Sponged:Data>
        SELECT *
        FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   2. Example for adding graph to Brad's graph group <urn:Brad:Sponged:Data>:
      

      
      -- No error will be raised as Brad has the efficient rights for graph group <urn:Brad:Sponged:Data>
      
      reconnect "Brad";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Brad:Sponged:Data>
        SELECT *
        FROM <http://brad-example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   3. Example for adding graph to Carl's graph group <urn:Carl:Sponged:Data>:
      

      
      -- An error will be rased because "Brad" has not enough rights on that group
      
      reconnect "Brad";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Carl:Sponged:Data>
        SELECT *
        FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
8. Examples check Carl's sponging permissions on different graph groups:
   1. Example for adding graph to Anna's graph group <urn:Anna:Sponged:Data>:
      

      
      -- An error will be rased because "Carl" has not enough rights on that group
      
      reconnect "Carl";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Anna:Sponged:Data>
        SELECT *
        FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   2. Example for adding graph to Brad's graph group <urn:Brad:Sponged:Data>:
      

      
      -- An error will be rased because "Carl" has not enough rights on that group
      
      reconnect "Carl";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Brad:Sponged:Data>
        SELECT *
        FROM <http://example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
   3. Example for adding graph to Carl's graph group <urn:Carl:Sponged:Data>:
      

      
      -- No error will be raised as Carl has the efficient rights for graph group <urn:Brad:Sponged:Data>
      
      reconnect "Carl";
      
      SPARQL
        DEFINE get:soft "replacing"
        DEFINE get:private <urn:Carl:Sponged:Data>
        SELECT *
        FROM <http://carl-example.com/>
        WHERE
          { ?s ?p ?o };
      

      
      
9. User Carl performs private sponging:
   

   
   
   reconnect "Carl";
   
   SPARQL
     DEFINE get:soft "replacing"
     DEFINE get:private <urn:Carl:Sponged:Data>
     SELECT *
     FROM <http://www.openlinksw.com/data/turtle/products.ttl>
     WHERE
       { ?s ?p ?o };
   
   -- Should return for ex. 365 rows.
   SPARQL
     DEFINE get:soft "replacing"
     DEFINE get:private <urn:Carl:Sponged:Data>
     SELECT COUNT(*)
     FROM <http://www.openlinksw.com/data/turtle/products.ttl>
     WHERE
       { ?s ?p ?o };
   
   
   SPARQL
     DEFINE get:soft "replacing"
     DEFINE get:private <urn:Carl:Sponged:Data>
     SELECT *
     FROM NAMED <http://www.openlinksw.com/data/turtle/software.ttl>
     FROM NAMED <http://www.openlinksw.com/data/turtle/licenses.ttl>
     WHERE
       {
         graph ?g
           { ?s ?p ?o
         }
       };
   
   
   -- Should return for ex. 1317 rows.
   SPARQL
     DEFINE get:soft "replacing"
     DEFINE get:private <urn:Carl:Sponged:Data>
     SELECT COUNT(*)
     FROM NAMED <http://www.openlinksw.com/data/turtle/software.ttl>
     FROM NAMED <http://www.openlinksw.com/data/turtle/licenses.ttl>
     WHERE
       {
         graph ?g
           { ?s ?p ?o
         }
       };
   

   
   
10. User Anna reads Carl's data:
    

    
    
    reconnect "Anna";   
    
    SPARQL
      SELECT COUNT(*)
      FROM <http://www.openlinksw.com/data/turtle/products.ttl>
      WHERE
        { ?s ?p ?o };
    
    callret-0
    INTEGER
    _______________________________________________________________________________
    
    365
    
    1 Rows. -- 15 msec.
    

    
    

Sponger Usage Examples

• SPARQL Processor Usage Example
• RDF Proxy Service Example
• Browsing & Exploring RDF View Example Using ODE
• Browsing & Exploring RDF View Example Using iSPARQL
• Basic Sponger Cartridge Example
• HTTP Example for Extracting Metadata using CURL
• RESTFul Interaction Examples
• Flickr Cartridge Example
• MusicBrainz Metadatabase Example
• SPARQL Tutorial -- Magic of SPARUL and Sponger

Related

• Example Performing Sponging on a entirely confidential database using get:private pragma
• Sponger's Linked Data Middleware Hooks into SPARQL
• Virtuoso Sponger
• Technical White Paper
• Supported Virtuoso Sponger Cartridges
• SPARQL Sponger
• Interacting with Sponger Middleware via RESTful Patterns
• Interacting with Sponger Meta Cartridge via RESTful Patterns
• Sponger Cartridge RDF Extractor
• Extending SPARQL IRI Dereferencing with RDF Mappers
• Programmer Guide for Virtuoso Linked Data Middleware ("Sponger")
• Create RDF Custom Cartridge Tutorial
• OpenLink-supplied Virtuoso Sponger Cartridges
• Virtuoso Authentication Server
• Virtuoso SPARQL OAuth Tutorial
• Virtuoso Sponger Access Control List (ACL) Setup
• WebID Protocol & SPARQL Endpoint ACLs Tutorial
• Virtuoso Documentation