How to clone a graph and set attribute of new subgraph efficiently?

Neo4j Graph Platform Cypher
, ,
2

Look into apoc.periodic.iterate and break the query up into two pieces -- the first enumerates what you have to do and the second takes that action on batches. This query probably won't work exactly, but it'll give you the right general process:

CALL apoc.periodic.iterate(
"MATCH (rootSkill:Skill{name: 'null'}),
(rootStudent:Student{id: '9f828c12-5134-409a-846e-bbc5a6463bff'})
CALL apoc.path.subgraphAll(rootSkill, {relationshipFilter:'PARENT>|DEPENDS_ON>'})
YIELD nodes, relationships
CALL apoc.refactor.cloneSubgraph(
  nodes,
  [rel in relationships WHERE type(rel) = 'PARENT' OR type(rel) = 'DEPENDS_ON'],
  { standinNodes:[[rootSkill, rootStudent]],
  skipProperties:['id'] })
YIELD input, output, error
RETURN output, rootStudent AS node",

"UNWIND
[{skill: "Skill 1", value: 0.9999999863}, {skill: "Skill 2", value: 0.3}]
as score
    WITH DISTINCT score, node, rootStudent
    WHERE node.name = score.skill
    SET node.id = apoc.create.uuid(), node.score = score.value
    WITH rootStudent
    MATCH (student:Student{id: '9f828c12-5134-409a-846e-bbc5a6463bff'})-[relation:PARENT]->(s:Skill)
    CREATE (student)-[learned:LEARNED {version: 1, created_at: timestamp()}]->(s)
    DELETE relation
    RETURN DISTINCT learned;
", 
    { batchSize: 1000, parallel: false });

Note I got rid of one of your UNWINDs. The first query feeds a stream of results to the second mutating query.

1 Like