Neo4j Cypher must all nodes have relation to root

Question

I am totally new on graph databases and neo4j. For study I have to implement friend structures for relational and graph databases. I finished with relational database and hang on neo4j because I find it very hard for beginners. So just a quick question: Must (or is it good graph style) have all nodes a relation to root node? I must implement search for friends of friend, relations between user which are not friends and so on. Using Webadmin/Neoclipse and neo4j 1.9.2.

Thank you.

Answer 1

The short answer is nope, you can completely ignore the root node, or in fact event delete it. There are no restrictions on node connectivities; one thing that is enforced, though, is that each relationship must have a start and an end node at all times (can be the same node).