Welcome William. William Waites wrote: > My collegue Paolo has been suggesting that I join this list for a > while
Lists :-) - [email protected] (first) - [email protected] (later, eventually) > Though I know there are ways to do this more efficiently, I think a > single CONSTRUCT query with some SERVICE blocks in the WHERE clause is > a very clean way to do it, and will only become more efficient as the > implementation gets better. When possible, I do this sort of things locally. I get a copy of the data I need or small slices of it, I load everything in TDB and run my SPARQL queries locally. > Secondly, I understand from Paolo that the client in ARQ does not use > persistent HTTP connections. Looking at HttpQuery.java [1] that seems to me to be the case (and it is probably ok for the majority of use cases). See also/related: "This feature is a basic building block to allow remote access in the middle of a query, not a general solution to the issues in distributed query evaluation. The algebra operation is executed without regard to how selective the pattern is. So the order of the query will affect the speed of execution. Because it involves HTTP operations, asking the query in the right order matters a lot. Don't ask for the whole of a bookstore just to find book whose title comes from a local RDF file - ask the bookshop a query with the title already bound from earlier in the query." -- http://incubator.apache.org/jena/documentation/query/service.html "SQUIN - Query the Web of Linked Data" http://squin.sourceforge.net/ Paolo [1] https://svn.apache.org/repos/asf/incubator/jena/Jena2/ARQ/trunk/src/main/java/com/hp/hpl/jena/sparql/engine/http/HttpQuery.java
