In transitive harvesting, source Catalog info is lost.
E.g.: Let's say node A and node B are two nodes in which datasets are created.
B harvests from A, so B contains datasets created locally, plus datasets created by A.
We then have a node C that harvests B. How can C find out which datasets belong to (i.e. were originally created on) B, and which datasets belong to A?
If we rely on the Catalog node only, it will seem that ALL datasets belong to catalog B, which isn't the case. So we should associate a new node to the dataset, that tells which is its original source catalog.
A solution is about using the dct:hasPart property, which expresses in pure DCAT semantic this requirement.
Let's say
Catalog C1 has Datasets D1a D1b
Catalog C2 has Datasets D2a D2b
C1 exposes a catalog.rdf as:
Catalog C1
Dataset D1a
Dataset D1b
C2 harvests from C1.
The related RDF could be expressed as:
Catalog C2 (URI, title, description, homepage)
Dataset D2a
Dataset D2b
dct:hasPart
Catalog C1 (URI, title, description, homepage)
Dataset D1a
Dataset D1b
(Original discussion was in geosolutions-it/ckanext-dcatapit#52, but ckanext-dcat is better suited for implementing this improvement.)
In transitive harvesting, source Catalog info is lost.
E.g.: Let's say node A and node B are two nodes in which datasets are created. B harvests from A, so B contains datasets created locally, plus datasets created by A.
We then have a node C that harvests B. How can C find out which datasets belong to (i.e. were originally created on) B, and which datasets belong to A? If we rely on the Catalog node only, it will seem that ALL datasets belong to catalog B, which isn't the case. So we should associate a new node to the dataset, that tells which is its original source catalog.
A solution is about using the
dct:hasPartproperty, which expresses in pure DCAT semantic this requirement.Let's say
C1 exposes a catalog.rdf as:
C2 harvests from C1. The related RDF could be expressed as:
dct:hasPart(Original discussion was in geosolutions-it/ckanext-dcatapit#52, but ckanext-dcat is better suited for implementing this improvement.)