Sebastian, "I started working on migrating to a couple of new libraries (most importantly: Sesame 4), but I didn't push those changes yet as they are pretty major. So the project isn't dead, and moving to Sesame 4 might actually improve a couple of things :)" ...
It looks like RDF4J is the successor of Sesame - is this the plan for Marmotta as well -or is progressing through later Sesame versions first the transition plan? Also, do any of these updates address the uploading / querying issue(s) mentioned above? Thanks On Fri, Mar 1, 2019 at 1:02 PM Sebastian Schaffert < sebastian.schaff...@gmail.com> wrote: > Hi, > > I started working on migrating to a couple of new libraries (most > importantly: Sesame 4), but I didn't push those changes yet as they are > pretty major. So the project isn't dead, and moving to Sesame 4 might > actually improve a couple of things :) > > SPARQL on H2 is not recommended, we only default to H2 because it offers > users a quick way to get started. If you want to get better performance, > I'd suggest you use PostgreSQL. The way we implement SPARQL is by > translating it into equivalent SQL and expecting the database query planner > to run it efficiently. PostgreSQL has a much better query planner than H2 > or MySQL for the kind of (graph) queries SPARQL generates. Another option > is to switch to the (experimental) Ostrich backend. It's not based on a > relational database and heavily optimized for large amounts of data, and > especially simple SPARQL queries will be much faster. But it's harder to > set up, and you'll need to compile the C++ backend for your platform. > > Can you file a couple of bugs for your feature requests? > > Sebastian > > Am Do., 28. Feb. 2019 um 08:08 Uhr schrieb Alan Snyder <alan8...@gmail.com > >: > >> Hi Noor, >> >> Thanks for reaching out! Our needs are to be able to store multiple >> Datasets (fragments), with versioning, transactions, SPARQL queries, REST >> endpoints for at least querying and updating, and some kind of persistence >> back-end we can back-up safely. Basically, we need git for RDF :) >> >> Marmotta fit the bill here and especially the versioning aspect was very >> attractive for us. However performance of SPARQL with our initial dataset >> (about 500k triples) was pretty bad (few seconds to a few minutes, >> depending). I'm new to SPARQL so maybe I wasn't optimizing the query as it >> should have been, but on other systems like GraphDb (granted - not an LDP >> platform), the same queries ran in sub-second timings. As I loaded more >> datasets, maybe totaling 3M triples, the response time was well into the >> minutes for things which should've been very fast, imho. I got frustrated >> after seeing a lot of java exceptions in the log file, and figured that >> maybe H2 wasn't the best for this dataset size. I tried MySQL and >> encountered an error where the 'triples' table wasn't created. I fixed that >> but queries were still long-running. I then switched to postgresql and got >> more errors about transactions I think, and at that point I gave up and >> felt that it needed more time to get setup right. I may come back to it but >> I need to move forward with something, so I'm looking at other options, >> along side learning RDF and SPARQL. Again, I may circle back to Marmotta, >> and likely will just to exhaust it as an option, but out fo the box, it >> didn't seem like it was usable. >> >> I'll take a look at your paper - that's interesting, Might be a bit >> overkill for our needs though. >> >> Thanks again, >> Alan >> >> >> >> >> >> >> >> On Thu, Feb 28, 2019 at 2:01 AM Mohammad Noorani Bakerally < >> noorani.bakera...@gmail.com> wrote: >> >>> Hi Alan, >>> >>> What type of LDP server are you looking for ? Do you need read >>> capability or write capability as well ? Because, in the last european >>> semantic web conference, I presented an approach for automating generating >>> LDPs from existing data sources. The LDPs can be hosted on any compatible >>> LDP server. For the purpose of the demonstration, I implemented a READ-only >>> LDP Server, here is a short paper ( >>> https://www.emse.fr/~zimmermann/Papers/eswc2018demo1.pdf) of 4 pages >>> describing the approach for generating the LDP and its deployment on the >>> server I developed. This approach was used to set up over 200 LDPs. >>> >>> If you intend to use this approach, feel free to get into contact, i can >>> help setting it up, >>> >>> thanks, >>> Noor >>> >>> >>> On Thu, Feb 28, 2019 at 3:49 AM Alan Snyder <alan8...@gmail.com> wrote: >>> >>>> Thanks for the info... we may be looking to use Marmotta for a project >>>> but was concerned about some the bugs I've encountered out of the box. For >>>> example, mysql doesn't seem to have a 'triples' table when I select that >>>> for the KiWi back-end... I had to create this manually. And even the >>>> Postgres setup gives some error I tried to track down. All in all, the >>>> feature set here is very close to what my needs are, but the above, and >>>> some performance issues with SPARQL when I tested it made me shy away. I'm >>>> willing to work on it to get things going, but I do have to consider other >>>> alternatives, at least other graph db's, if not full blown LDP platforms. >>>> >>>> I'd love to hear more updates and chatter here (and on the dev >>>> channel). I think going to RDF4J is a great start too - and maybe I can try >>>> to fix the mysql and Postgres issues once I track down where those DDL >>>> files are. >>>> >>>> Thanks again! >>>> Alan >>>> >>>> >>>> >>>> >>>> >>>> >>>> On Wed, Feb 27, 2019 at 3:49 PM Xavier Sumba < >>>> xavier.sumb...@ucuenca.edu.ec> wrote: >>>> >>>>> Hello all, >>>>> >>>>> We can propose something for GSoC 2019 with the aims of reviving the >>>>> project and attract contributors. What do you think Jakob? >>>>> >>>>> I can try to finish the migration to RDF4J if I find some free time. >>>>> :D >>>>> >>>>> In the meantime Alan, if you'd like to contribute with something the >>>>> migration is a good start [1], and IMHO, it was a matter of moving to the >>>>> version 3.4.0 and solving some naming conventions. I think for now we can >>>>> avoid the experimental backends. >>>>> >>>>> >>>>> Best, >>>>> Xavier >>>>> >>>>> [1] https://github.com/apache/marmotta/pull/31 >>>>> >>>>> >>>>> > On Feb 27, 2019, at 15:22, Jakob Frank <jakob.fr...@redlink.co> >>>>> wrote: >>>>> > >>>>> > Hi Alan, >>>>> > >>>>> > I'd say dormant, not dead. >>>>> > >>>>> > To be frank: Development activities have been rather low in the past >>>>> months. >>>>> > Any help is appreciated, so if you'd like to contribute something you >>>>> > are more than welcome! >>>>> > >>>>> > Best, >>>>> > Jakob >>>>> > >>>>> > >>>>> > On Wed, 27 Feb 2019 at 15:27, Alan Snyder <alan8...@gmail.com> >>>>> wrote: >>>>> >> >>>>> >> Thanks Aaron.. just to be clear.. Is Marmotta a dead project now? >>>>> There was just a release in June for 3.4.0 so I hoped there'd be some >>>>> momentum.. any plans for future work here? >>>>> >> >>>>> >> >>>>> >> >>>>> >> On Wed, Feb 27, 2019, 9:03 AM Aaron Coburn <acob...@amherst.edu> >>>>> wrote: >>>>> >>> >>>>> >>> Hi, >>>>> >>> if you are looking for an LDP server, the Apache Annotator project >>>>> (Web Annotation Protocol sits atop LDP) has a list of implementations on >>>>> this page: >>>>> >>> >>>>> >>> >>>>> https://github.com/apache/incubator-annotator/wiki/LDP-and-Web-Annotation-Protocol-Implementations >>>>> >>> >>>>> >>> Other than Virtuoso, which is a commercial product, all of the >>>>> projects listed are Apache 2 licensed. >>>>> >>> >>>>> >>> -Aaron >>>>> >>> >>>>> >>> On Tue, Feb 26, 2019 at 3:20 PM Alan Snyder <alan8...@gmail.com> >>>>> wrote: >>>>> >>>> >>>>> >>>> Hi, just wondering if this project is still active? I don't see >>>>> any activity in the mailing list archives. Is there another venue for >>>>> communication with the team? And if the project isn't worked on routinely, >>>>> is there another platform recommended to use with similar features / >>>>> license? >>>>> >>>> >>>>> >>>> Thanks! >>>>> >>>> Alan >>>>> >>>> >>>>> > >>>>> > >>>>> > -- >>>>> > Jakob Frank >>>>> > | http://redlink.at >>>>> > | m: +43 699 10588742 | e: jakob.fr...@redlink.at >>>>> > | http://at.linkedin.com/in/jakobfrank >>>>> >>>>> >>>>> -- >>>>> Advertencia legal: >>>>> Este mensaje y, en su caso, los archivos anexos son >>>>> confidenciales, especialmente en lo que respecta a los datos >>>>> personales, y >>>>> se dirigen exclusivamente al destinatario referenciado. Si usted no lo >>>>> es y >>>>> lo ha recibido por error o tiene conocimiento del mismo por cualquier >>>>> motivo, le rogamos que nos lo comunique por este medio y proceda a >>>>> destruirlo o borrarlo, y que en todo caso se abstenga de utilizar, >>>>> reproducir, alterar, archivar o comunicar a terceros el presente >>>>> mensaje y >>>>> ficheros anexos, todo ello bajo pena de incurrir en responsabilidades >>>>> legales. Las opiniones contenidas en este mensaje y en los archivos >>>>> adjuntos, pertenecen exclusivamente a su remitente y no representan la >>>>> opinión de la Universidad de Cuenca salvo que se diga expresamente y >>>>> el >>>>> remitente esté autorizado para ello. El emisor no garantiza la >>>>> integridad, >>>>> rapidez o seguridad del presente correo, ni se responsabiliza de >>>>> posibles >>>>> perjuicios derivados de la captura, incorporaciones de virus o >>>>> cualesquiera >>>>> otras manipulaciones efectuadas por terceros. >>>>> >>>>
