Hi Ivan, Jorn, I've run into similar requirements. A catch-all solution to this could be to surface the ability to specify a custom deref procedure
define input:iri_deref "DB.DBA.MY_CUSTOM_IRI_DEREF" This should get all the context to decide whether to perform a fetch and also have access to the sponger infrastructure. This is a broad and raw idea, I know. The point is that the current visibility into what happens under the covers is too low. Of course, in an ideal world, sources should play along with the Linked Data rules ( including specifying caching TTL ) but in reality you might want to override some sources, implement specific caching strategies, etc. Spongers provide some flexibility in the "how do I get stuff from a IRI" part. But perhaps the controller part could also be "extensible". As usual, the smartest way to go about this is wait until there are enough use cases. I see virtuoso-users is picking up some speed ;) Regards, A On Sat, Jul 31, 2010 at 12:18 AM, Ivan Mikhailov <[email protected]> wrote: > Hello Jörn, > >> is there any way to configure the sponger behind this to >> 1. cache its lookups, so don't retrieve graphs already present in the local >> quad store (the DEFINE get:soft "soft" seems to be what I want, but that only >> works for graphs mentioned in a FROM or FROM NAMED clause), > > It caches things by default and control the expiration of cached copies > by returned HTTP header lines. If a remote tells that the resource > should not be cached or sets very small expiration time then the cache > lifetime can not be lengthen. define get:refresh can force earlier > reloading but can not delay it: it sets maximum allowed refresh time, > not a strict value. > >> 2. do n-fetches in parallel and/or, > > It tries to fetch in parallel, via async_queue-s of "width" 8. > Unfortunately that happens not in all cases. > >> 3. tell me if some object turned out not to be a linked data resource, but >> just an URL (e.g., in the triple: (dbpedia:Barack_Obama dbpprop:reference >> <http://www.chicagolife.net/content/politics/Barack_Obama>) ) > > I'll think what can be done. Right now there's nothing ready-to-use, > because we follow Squids strategy and cache only good results, not > failures. However it's possible to make sample RDF view to render data > from table DB.DBA.SYS_HTTP_SPONGE and get access to status of currently > cached copies. > > Best Regards, > > Ivan Mikhailov > OpenLink Software > http://virtuoso.openlinksw.com > > > > ------------------------------------------------------------------------------ > The Palm PDK Hot Apps Program offers developers who use the > Plug-In Development Kit to bring their C/C++ apps to Palm for a share > of $1 Million in cash or HP Products. Visit us here for more details: > http://p.sf.net/sfu/dev2dev-palm > _______________________________________________ > Virtuoso-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/virtuoso-users > -- Aldo Bucchi @aldonline skype:aldo.bucchi http://aldobucchi.com/ PRIVILEGED AND CONFIDENTIAL INFORMATION This message is only for the use of the individual or entity to which it is addressed and may contain information that is privileged and confidential. If you are not the intended recipient, please do not distribute or copy this communication, by e-mail or otherwise. Instead, please notify us immediately by return e-mail.
