Edges, Identifiers, Handles

A graph data model always consists of at least two collections: the relations between thenodes in the graphs are stored in an “edges collection”, the nodes in the graphare stored in documents in regular collections.

Example:

• the “normal” collection stores all the properties about the reception, e.g. that 20 people are working there and the room number etc
• _to is the document handle of the linked vertex (outgoing relation)Edge collections are special collections that store edge documents. Edge documents are connection documents that reference other documents. The type of a collection must be specified when a collection is created and cannot be changed afterwards.

Edges are normal that always contain a and a _to attribute.