- From: Chimezie Ogbuji <ogbujic@ccf.org>
- Date: Tue, 29 Sep 2009 09:31:48 -0400
- To: "Seaborne, Andy" <andy.seaborne@hp.com>, "SPARQL Working Group" <public-rdf-dawg@w3.org>
/me reminisces over Versa On 9/29/09 7:12 AM, "Seaborne, Andy" <andy.seaborne@hp.com> wrote: > I've tried to list the main possibilities in terms of styles and approach as > starting points: all have variations and areas of uncertainty (e.g. ordering > of results). > > 1/ Property paths only mention IRIs or prefixed names. In Versa's forward traversal operators, the properties along the paths could only be restricted via explicit URI ref (Qname, etc.). subjects - predicates -> boolean "[..]Statements that have matched the first criteria (the subjects expression) are examined and excluded if their predicate is not a member of this resulting list." So predicate matching can only be done directly or WRT the URIs of the resources that are subjects of the path So I favor this. > The most conservative choice. Still need to relate to entailment. It should be easy to relate to entailment as no 'new' names are introduced. > 2/ Property paths with variables and IRIs or prefixed names. > (issues include restriction of what can be asked a la ?p* discussion) -1 > 3/ With access to the length of the path matched > Issues include how multiple paths between two nodes are handled (two lengths > possible). Versa didn't have a way to filter by the length of a path traversed except as a 'callout' to a transitive closure query that returned the path. This might have computational implications -1 -- Chime =================================== P Please consider the environment before printing this e-mail Cleveland Clinic is ranked one of the top hospitals in America by U.S. News & World Report (2008). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. Thank you.
Received on Tuesday, 29 September 2009 13:33:22 UTC