LarKC Tutorial at ISWC 2009 - Data Model

LarKC Data Layer Early adopter’s workshop

Objectives
To provide a standard API for RDF persistence
To implement different strategies of data passing (by value vs. by reference)
To realize efficient RDF statement meta-data association
To offer utility model to simplify common RDF data management tasks

ORDI Data Model
RDF model states universal-true
Named graphs do not ensure the required flexibility to model complex context/meta-data
Provenance of the information
Author / time stamp created / selection
Isolate data from the meta-data on RDF model level

ORDI Data Model Semantics
Neutral in terms of semantics
Well defined data model operations
add – asserts new RDF statement
remove – retract an RDF statement
associate – add statement to a labelled group
deassociate – remote statement from a labelled group

ORDI Data Model Example
Operations
add(a:alice, foaf:name, “Alice”, ng:g1)
add(b:bob, foaf:knows, a:alice, ng:g2, {l:l1})
add(a:alice, foaf:name, “Alice”, ng:g2)
associate(a:alice, foaf:name, “Alice”, ng:g1, l:l2)
remove(a:alice, foaf:name, “Alice”, ng:g2)
Alice foaf:name foaf:knows foaf:name b:bob a:alice ng:g1 ng:g2 L1 L2 L2 L3

Used Concepts in the Data Model NG1 NG3 NG4 NG5 NG2 Labelled groups of statements Labelled groups of statements

Supported Sets of Statements RDF data types Description Example Set of statement RDF statements s1, p1, o1, ng1 s2, p2, o2 s3, p3, o3, ng3, {group1} RDF graph Named graph s1, p1, o1, ng1 , {group1} s2, p2, o2, ng1 , {group2} s3, p3, o3, ng1 Dataset SPARQL dataset represents a collection of graphs s1, p1, o1, ng1 s2, p2, o2, ng2 s3, p3, o3, ng3 Labelled group of statements RDF group of statements s1, p1, o1, ng1, {group1} s2, p2, o2, ng2, {group1} s3, p3, o3, ng3, {group1}

Java Interfaces to Implement the RDF Types

Java Interfaces to Create the RDF Types

The Different Implementations Name Purpose Cost to pass 10 6 RDF statements Set of statements Services to return RDF data (e.g., SPARQL construct and describe queries) 350MB memory Named graph in memory Pass named graphs between plug-ins 350MB memory HTTP published RDF graph Load chunks of RDF from URL few KBs + time to load the data Named graph retrieved from a SPARQL endpoint Pass named graphs using a SPARQL endpoint few KBs + time to transfer the data + to filter the dataset with SPARQL SPARQL dataset Constrain RDF data exposed by a SPARQL endpoint with a list of graph names few KBs + time to transfer the data + to filter the dataset with SPARQL Labelled group of statements Pass arbitrary sets of RDF statements between plug-ins (e.g., graph priming) few KBs + time to associate the statements + time to filter the labelled group

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LarKC Tutorial at ISWC 2009 - Data Model

by LarKC on Nov 04, 2009

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LarKC Tutorial at ISWC 2009 - Data Model — Presentation Transcript