incubator-clerezza-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Olivier Grisel <ogri...@nuxeo.com>
Subject Re: A question about Jena Sparql Engine and the TDB Store
Date Fri, 18 Mar 2011 13:39:22 GMT
On 18 March 2011 14:19, Reto Bachmann-Gmuer <reto.bachmann@trialox.org> wrote:
> On Fri, Mar 18, 2011 at 12:31 PM, Olivier Grisel <ogrisel@nuxeo.com> wrote:
>>
>> On 18 March 2011 12:22, Reto Bachmann-Gmuer <reto.bachmann@trialox.org> wrote:
>> > I was convinced that sparql-fastlane wasa laready an issue, but it doesn't
>> > seem to.
>> >
>> > Thanks for adding the issues.
>>
>> Actually I found one:
>>
>>  https://issues.apache.org/jira/browse/CLEREZZA-194
>>
>> But for some reason it was closed as "won't fix". I linked it to
>> CLEREZZA-466 for reference.
>
> I undesrstood the issue CLEREZZA-194 as a suggestion to replace the
> arq based implementation with another one, so basically as providing
> another implementation of
> org.apache.clerezza.rdf.core.sparql.QueryEngine. The fastlane approach
> (mentioned in the comments on to issue 194) is different as allows
> support for endpoint that are tied to the storage.

Ok.

> I've added CLEREZZA-468 which comprises the needed changes in SCB core
> and marked 466 as depending on it. I'm not sure about CLEREZZA-467, it
> is currently possible (afaik) to run a query against multiple graphs
> using FROM and FROM NAMED clauses, with a resolution of CLEREZZA-468
> and 466 such a query would be forwarded to the tdb.storage provider
> and has to be handled - not sure how the state between the resolution
> of 466 and 467 is supposed to look like.

I might be wrong but I thinkg the Jena TDB store will be able to
perform multiple named graphs queries much more efficiently if all the
graphs involved by the query belong to the same TDB store rather that
going through a generic indirection involving a generic wrapper. Would
be worth checking that claim by reading the jena source code though.

-- 
Olivier

Mime
View raw message