Create Link failure

[Andreas Dernbauer]

I tried to connect to graphs by using a Bridge table

MATCH (a:dwhElement),(b:aifElement),(c:dwh2aif)

where a.ElementID = c.dwhElementID and c.aifElementID = b.ElementID  

CREATE (a)-[r:dwh_FEEDS_aif]->(b)

return r; 

After at least one hour I got as result uknown error,

MATCH (a:dwhElement)

return count(a);

returns 3842 rows

MATCH (a:aifElement)

return count(a);

returns 938 rows

MATCH (a:dwh2aif)

return count(a);

returns 2755 rows

MATCH (a:dwhElement),(b:dwh2aif)

where a.ElementID = b.dwhElementID

return count(a),count(b);

count(a) = 2755

count(b) = 2755

Any Ideas ? 

Thank you 

[Andreas Dernbauer]

If I run that query with access DB I got a result back in 1 second 

SELECT dwhElement.dwhSysID, dwhElement.dwhStructID, dwhElement.dwhElementName, aifElement.aifElememtID, aifElement.aifSysID, aifElement.aifStructID, aifElement.aifElementName

FROM (dwhElement INNER JOIN dwh2aif ON dwhElement.dwhElememtID = dwh2aif.dwhElementID) INNER JOIN aifElement ON dwh2aif.aifElementID = aifElement.aifElememtID;

[Michael Hunger]

I think you just create a cross product here. 3842* 938* 2755

try this

create index on :dwhElement(ElementID);

create index on :aifElement(ElementID);

MATCH (c:dwh2aif)

match (a:dwhElement)

where a.ElementID = c.dwhElementID

match (b:aifElement)

WHERE c.aifElementID = b.ElementID  

CREATE (a)-[r:dwh_FEEDS_aif]->(b)

return r; 

you can look at your query plan if you prefix your query with EXPLAIN or PROFILE (also runs it)

--
You received this message because you are subscribed to the Google Groups "Neo4j" group.
To unsubscribe from this group and stop receiving emails from it, send an email to neo4j+un...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Andreas Dernbauer]

Hi Michael 

Thank you for you answer, I created indexes of course without any success.

I tried explain but I got back

• neo4j-sh (?)$ EXPLAIN match(a: dwhSystem) return a;
• ==> Unknown command 'explain'
• neo4j-sh (?)$ 

[Michael Hunger]

Which Neo4j version are you using? Explain is only in 2.2 ?

For previous versions use PROFILE.

M