forked from D-Net/dnet-hadoop
22 lines
1.4 KiB
Markdown
22 lines
1.4 KiB
Markdown
Joins the graph nodes by resolving the links of distance = 1 to create an adjacency list of linked objects. The
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operation considers all the entity types (publication, dataset, software, ORP, project, datasource, organization, and
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all the possible relationships (similarity links produced by the Dedup process are excluded).
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The operation is implemented by sequentially joining one entity type at time (E) with the relationships (R), and
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again by E, finally grouped by E.id;
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The workflow is organized in different parts aimed to to reduce the complexity of the operation
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1) PrepareRelationsJob: only consider relationships that are not virtually deleted ($.dataInfo.deletedbyinference ==
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false), each entity can be linked at most to 100 other objects
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2) CreateRelatedEntitiesJob: (phase 1): prepare tuples [relation - target entity] (R - T): for each entity type
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E_i map E_i as RelatedEntity T_i to simplify the model and extracting only the necessary information join (R.target =
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T_i.id) save the tuples (R_i, T_i) (phase 2): create the union of all the entity types E, hash by id read the tuples
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(R, T), hash by R.source join E.id = (R, T).source, where E becomes the Source Entity S save the tuples (S, R, T)
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3) AdjacencyListBuilderJob: given the tuple (S - R - T) we need to group by S.id -> List [ R - T ], mapping the
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result as JoinedEntity
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4) XmlConverterJob: convert the JoinedEntities as XML records
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