Hi Andy, Thanks for your suggestions! I'm more interested in JENA-625 (Data Tables for SPARQL). I've seen your new comments in JIRA and studied the source code of Tarql. I'd like to paste your comments here with my questions below to clarify the details of this project:
1. CSV to RDF terms (tuples of RDF Terms is already supported internally in Jena) - Questions: 1.1 Tarql uses the first row of CSV as variable names. Should we use the same idea? 1.2 As to "internal support of tuples of RDF terms in Jena", do you mean com.hp.hpl.jena.sparql.algebra.table.TableData? Tarql uses TableData to accommodate RDF term bindings from CSV. 2. Storage of the table (in-memory is enough, with reading from a file). - Questions: 2.1 What's the life cycle of the in-memory table? Should we discard the table after the query execution, or keep it in-memory for later reuse with the same query or update, or use by a subsequent query? When will the table be discarded? 3. Modify the SPARQL grammar to support FROM TABLE and TABLE (for inclusion inside a larger query, c.f. SPARQL VALUES clause). - Questions: 3.1 What're the differences between FROM TABLE and TABLE? 3.2 Tarql programmatically modify the query (parsed from standard SPARQLParser11) with CSV tabsle data without touching the orginal SPARQL grammar parsing module. Should we adopt a different approach of modifying the parsing grammar of .jj files and just ask javacc to generate the new parsing code? 4. Modify execution to include tables. Questions: No questions for this now. Best regards, Ying Jiang On Thu, Feb 27, 2014 at 10:49 PM, Andy Seaborne <[email protected]> wrote: > On 26/02/14 15:14, Ying Jiang wrote: >> >> Hi, >> >> With the great guidance from the mentors, especially Andy, I had a >> good time in GSoC 2013 working on jena-spatial [1]. I'm very grateful. >> Really learnt a lot from that project. >> >> This year, I find the issue of "Extend CONSTRUCT to build quads" [1] >> very interesting. I've used javacc before. I can understand the ARQ >> module of parsing SPARQL strings. With a label of "gsoc2014", is it a >> suitable project for Jena in GSoC 2014? Any more details about the >> project? Thanks! >> >> Best regards, >> Ying Jiang >> >> [1] http://jena.apache.org/documentation/query/spatial-query.html >> [2] https://issues.apache.org/jira/browse/JENA-491 >> > > Hi there, > > Given your level of skill and expertise, this project is possibly a bit > small for you. It's not the same scale as jena-spatial. It's probably more > suited to an undergraduate or someone looking to learn about working inside > a moderately large existing codebase. You have a lot more software > engineering experience. > > Can I interest you in one of: > > * JENA-625 especially the part about CSV ingestion. There is now a W3C > working group looking at tabular data on the web so we know this is > interesting to the user community. > > * JENA-647, (only just added) which is server side query templates for > creating data views. > > In conjunction with someone (else) doing JENA-632 (custom JSON from SPARQL > query), we would have a data delivery platform for creating domain specific > data delivery for webapp. > > (this was provided in the proprietary Talis platform as "SPARQL Stored > Procedures" but that no longer exists. No need to exactly follow that but > it was a popular feature so it is useful). > > * JENA-624 which is about a new memory-based storage layer. As a project, > its nearer in scale to jena-spatial. This is less about RDF and linked data > and more about systems programming. > > Andy >
