Re: updating persisten jena-fuseki dataset increases memory consimption in gigas

Hi, Thanks for your quick anserwer and pls see my answers below! How many triples? And is is new data to replace the old data or in addition to the existing data? 476955 triplets, most parts will bu just same as the old data, just some triplets may change. And some new triplets may be

Need help about creating a subquery inside a construct using ARQ

Hi, I am trying to build the following query using ARQ PREFIX ldp: CONSTRUCT { ?a ldp:member ?b . } WHERE { SELECT ?b WHERE { GRAPH ?d { ?b ldp:memberOf ?a } GRAPH ?b { ?r ldp:memberOf ?s } } } I

Re: updating persisten jena-fuseki dataset increases memory consimption in gigas

Hi Jaana, On 09/03/2021 11:40, jaa...@kolumbus.fi wrote: hello, I've met the following problem with jena-fuseki (should I create bug ticket ?): We need to update jena-fuseki dataset every 5 minutes by a 50 Mbytes ttl-file. How many triples? And is is new data to replace the old data or

Re: Paging data with Jena

When possible, I'm using some partitioning strategy and split a big set of entities between several graphs; so, the response time for each graph is acceptable, but it push some complexity to the application and the queries. For example, with a lot of entities with a date property, I split the set

Re: Paging data with Jena

Are you using TDB? Because it does have indices: https://jena.apache.org/documentation/tdb/architecture.html#triple-and-quad-indexes On Tue, 9 Mar 2021 at 17.58, Donald McIntosh wrote: > Thanks all for replies. > > Jean-Claude - yes I assume the same. It just scrolls through until it > gets

Re: Paging data with Jena

Thanks all for replies. Jean-Claude - yes I assume the same.  It just scrolls through until it gets to the offset, which means the query runtime will scale exactly with size of the offset with no optimizations or re-use between executions to make it faster.  Without indexes, I cannot see a

ApacheCon Call for Papers

Greetings, We have an RDF / Linked Data track at ApacheCon this year. If you are working on a project that uses Jena we would like to hear from you. Please submit paper proposals at https://acah2021.jamhosted.net/ Thank you, Claude

updating persisten jena-fuseki dataset increases memory consimption in gigas

hello, I've met the following problem with jena-fuseki (should I create bug ticket ?): We need to update jena-fuseki dataset every 5 minutes by a 50 Mbytes ttl-file. This causes the memory consumption in the machine where jena-fuseki is running to increase by gigas. This was 1st detected

Re: Paging data with Jena

I think we have there a performance issue. When the complete result is big, and you take a slice with LIMIT/OFFSET, i suspect the Jena implementation is going through the dataset until the offset, then it get the result. It doesn't take advantage of a previous offset/limit with the same query; so,

Re: Paging data with Jena

just some comments as you already got the answer: pagination in SPARQL can only be done via limit + offset, as you already have figured out - but, formally, it is only guaranteed to be correct when sorting the data. depending on the size of the data this can be expensive - especially what

Re: Paging data with Jena

COUNT(*) / LIMIT should give you the number of pages. On Tue, Mar 9, 2021 at 9:52 AM Donald McIntosh wrote: > > Hi.. > > I have an implementation where I would like to page through data retrieved > via a SPARQL query on Apache Jena on a UI. offset and limit features take me > some of the way

Paging data with Jena

Hi.. I have an implementation where I would like to page through data retrieved via a SPARQL query on Apache Jena on a UI. offset and limit features take me some of the way there but do not tell me the full size of the overall result set so that users can skip to the end or to page x knowing