Rahul Patil wrote:
Hi All,
Rather a simple (may be stupid) SPARQL question.
Is it possible to get total number of results back for a SPARQL query;
without actually getting all the results back? like ASK tells if results
are present; Is there anything which tells how many of them are present?
Hi Rahul,
It's not a stupid question at all. SPARQL does not provide a standard
way to do this (a la COUNT in SQL).
However, many SPARQL implementations do extend the language with support
for COUNT. Some examples include:
ARQ (http://seaborne.blogspot.com/2007/09/counting-and-group-by.html)
Virtuoso (http://docs.openlinksw.com/virtuoso/rdfsparqlaggregate.html)
ARC (http://arc.semsol.org/docs/v2/sparql+)
RAP
(http://www.informatik.uni-leipzig.de/~auer/publication/sparql-enhancements.pdf)
Glitter
(http://www.thefigtrees.net/lee/blog/2007/10/announcing_open_anzo_25_releas.html)
More generally, I'm working to add information on this and other common
SPARQL extensions to the ESW Wiki and the SPARQL FAQ; I'll post here
when I've done that.
Lee
