On 2017-09-12 10:34, Andy Seaborne wrote: > FROM / FROM NAMED create a dynamic dataset for TDB which id a subset of > all graphs. > > https://jena.apache.org/documentation/tdb/dynamic_datasets.html > > The for this is in org.apache.jena.sparql.core.DyanmicDatasets
I will look at it, as it seems what I want to do. > Andy > > On 11/09/17 13:40, George News wrote: >> On 2017-09-08 20:18, Andy Seaborne wrote: >>> Yes, Chris - MultiUnion is linking with a distinguished that is updated. >>> (Changing that would be a BIG change!) >>> >>> Datasets like TIM (transactions in memory) and TDB can provide the union >>> graph of their named graphs and more efficiently than the general >>> purpose >>> MultiUnion. >> >> Previously I was using the "urn:x-arq:UnionGraph" named graph, but now I >> need to be less generic and only include some of them. This is why I >> have to work with the other options :( >> >> >>> Andy >>> >>> On 8 September 2017 at 13:52, Chris Dollin >>> <[email protected]> >>> wrote: >>> >>>> On 8 September 2017 at 10:11, George News <[email protected]> wrote: >>>> >>>>> Hi, >>>>> >>>>> Is multiunion only linking the graphs or copying them in a new graph? >>>>> >>>>> I'm thinking on splitting a huge graph on many simple ones and them >>>>> making the union depending on the part of the main graph that has >>>>> to be >>>>> requested, therefore limiting the scope of the sparql and speeding >>>>> things up. But if multiunion copies, then I don't think I will speed >>>>> things. >>>>> >>>> >>>> If things haven't changed too much ... >>>> >>>> (a) it links the graphs. They are not copied. Hooray! >>>> >>>> (b)ut when you run an operation over the graph that delivers >>>> a set of triples (which is how queries work over union graphs) >>>> it has to remember all the triples it has already seen so that it >>>> doesn't deliver duplicates. Hence (depending on the triple >>>> pattern being used) may mean lots of store being held onto. >>>> Alas! >>>> >>>> Chris >>>> >>>> -- >>>> "What I don't understand is this ..." Trevor Chaplin, /The Beiderbeck >>>> Affair/ >>>> >>>> Epimorphics Ltd, http://www.epimorphics.com >>>> Registered address: Court Lodge, 105 High Street, Portishead, >>>> Bristol BS20 >>>> 6PT >>>> Epimorphics Ltd. is a limited company registered in England (number >>>> 7016688) >>>> >>> >
