[Myexperiment-discuss] Upgraded myExperiment SPARQL endpoint

[David R Newman]

Hi All,

 

I have been working on upgrading myExperiment’s SPARQL endpoint to use 4Store (http://www.4store.org) from JENA.  This should make it much quicker at finding results than it has been in the past.  I am currently running a test instance of the 4Store-backed SPARQL endpoint at http://rdf.myexperiment.org/sparql4.  So if people want to try out some of their more complex SPARQL queries to see if they run quicker that would be most appreciated.

 

I have endeavoured to maintain all the previous functionality in as similar way as possible but inevitably there are some differences:

 

-           No JSON results format

-          4Store does not have a way of timing out queries that take too long.  They either return only partial results and/or send a warning message about the complexity.  Instead of a timeout option I have provided a “Resource Usage” option.  This is defaulted to 5% which is suitable for most basic queries but if you get a warning saying that a query could not return all results then increasing this percentage should help.

 

In theory the endpoint should be updated each morning much like the current endpoint but I have only just sorted out the scripts to do this and I wouldn’t want to guarantee their reliability at the moment.

 

Anyway, any comments/feedback would be most appreciated.

 

Regards

 

David Newman