graph-databases

I am still trying to understand why I get a cartesian product warning for a certain format for a query in neo4j and not for another. This is how I set up my database: CREATE (q:Form {version: "1.0"}) CREATE (q:Question {text: "Sector de la empresa", active: true}) I then tried the following query: MATCH (f:Form {version: "1.0"}), (q:Question {text: "Sector de la empresa"}) CREATE (f)-[:asks]->(q) RETURN f, q However, I get the following warning: This query builds a cartesian product between disconnected patterns. If a part of a query contains multiple disconnected patterns, this will build a

NOTE: I am using a graph database (OrientDB to be specific). This gives me the freedom to write a server-side function in javascript or groovy rather than limit myself to SQL for this issue.* NOTE 2: Since this is a graph database, the arrows below are simply describing the flow of data. I do not literally need the arrows to be returned in the query. The arrows represent relationships.* I have data that is represented in a time-flow manner; i.e. EventC occurs after EventB which occurs after EventA, etc. This data is coming from multiple sources, so it is not completely linear. It needs to be

I am just getting started with Neo4j and Graph Databases and was wondering if nested hierarchical trees are a good use case for Neo4j. A common example would be a nested set of comments. For example: - Article - Comment 1 on Article - Comment 2 on Comment 1 - Comment 3 on Comment 1 - Comment 4 on Comment 3 - Comment 5 on Article As I understand it, the article and the comments would each be nodes. And each comment would have a parent-child relationship. Getting all direct comments on the article (1 and 5) would be easy. But how about retrieving the whole set? Please excuse the use of layman

I'm considering a setup where I have entities stored both in a document db (e.g. CouchDB) and a graph db (e.g. Neo4j). The rationale is storing each entity information (data, blobs, values, complex internal structure) in the document db while storing the entity relations (parents, children, associated entities) in the graph db. Has anyone done / seen / been bitten by a setup like this? What kind of issues should I expect? First thing that come to mindaka the 2-phase commit. But backups are problematic too here. You may check out the book " Seven DBs in Seven Weeks ". 8th chapter talks about