Clarify in the README how the data is modeled in LevelGraph

[mcollina]

From @lanthaler:

Makes sense.. You should probably clarify that in the readme though as I believe a lot of people would otherwise assume that they get the same document back in a get.

[elf-pavlik]

@lanthaler do you know if we could extract frame from input document before/while deserializing it into triples/quads with jsonld.js toRDF() ? we could then save it and provide option to use it on get as we start brainstorming framing in #2

[lanthaler]

Sorry, but I don’t think I understand what you are saying. Why don’t you simply store the input document as is if you want to restore its structure?

[elf-pavlik]

good point! :smile:

i posted hopefully more clearly stated question to json-ld mailing list: http://lists.w3.org/Archives/Public/public-linked-json/2013Dec/0005.html

[elf-pavlik]

Closing since I already have added paragraph saying:

Please keep in mind that LevelGraph-JSONLD doesn't store the original JSON-LD document but decomposes it into triples!

framing we can discuss in #2 and #8 more detailed information we can add after resolving #4 and #5

[elf-pavlik]

I start realizing usefulness of storing somewhere original document which we decompose into triples. We could maybe use triple properties to somehow reference document from which given triple origins. No clue ATM where we could store those original documents...

[mcollina]

I agree! You can store them using they id, but you would need to get down one level and just use levelup, e.g storing them using the main @id. obj:: http://iamaniri.org/matteo

However, as we are duplicating data, we need to take great care in avoiding differences.

Il giorno domenica 22 dicembre 2013, ☮ elf Pavlik ☮ ha scritto:

I start realizing usefulness of storing somewhere original document which we decompose into triples. We could maybe use triple properties to somehow reference document from which given triple origins. No clue ATM where we could store those original documents...

— Reply to this email directly or view it on GitHubhttps://github.com/mcollina/levelgraph-jsonld/issues/1#issuecomment-31096508 .

[elf-pavlik]

It can get tricky with using @id IRI since some document may not have main resource at all eg. serialized array. At this moment I can think of few possible approaches:

• if document comes for making HTTP request one can just use it's IRI (maybe + timestamp or HTTP ETag?)
• generating UUIDs
• creating hash of original document

At first I would consider starting with something simple like generating UUIDs or hash just so we can somehow reference the original document for which given statement came from! Which might get even more interesting once we get to implementing SPARQL...

We may also need to give a good thought on handling cases of documents with embedded (nested) resources. I can imagine case of someone first creating a resource using big number of statements and then inserting another document with same resource embedded but only including few relevant statements. We can NOT just delete all the statement about this resource and replace them with just those few statements from embedded one! I would prefer not to get into this topic in more depth here and maybe I'll create separate issue for it... previous issue relevant this topic #8 I would prefer to leave for discussing blank nodes -- a big topic on its own :wink:

BTW I have impression that we deal lately here with many general RDF specific issues relevant not only to JSON-LD serialization...

[mcollina]

JSON-LD is RDF, and we are developing an RDF data storage on top of LevelGraph. I think having a separate issue is better. Also, can you create a 'v0.3.0-wip' pull-request with all the stuff that you plan to release there?

[elf-pavlik]

I've just renamed #10 to v0.3.0-wip and would only like to include #11 in it before merging!

Discussion about which issues relate to RDF in general and which issues stay specific to its various serializations we can continue elsewhere...

[elf-pavlik]

I just play around with parsing my maildir with http://npm.im/mailparser , generating UUID based Skolem IRI for @id, adding @context just with some bogus @vocab and saving it in LevelGraph.

@mcollina could you imagine writing small snippet suggesting how would you go about storing original source of each email in LevelDB maybe simply using generated UUID as key? For now I would just look at adding an additional property with this UUID to each stored triple...

[mcollina]

Cool project!

I suggest to use sublevel, and you can use one sublevel for the graph in which you store the email's metadata, plus one sublevel for the email parts. How does it sound?