FIWARE Orion and user data management vs mysql database

Question

I was asked to create a backend server for storing and managing user information data, specifically using Orion Context Broker. How can Orion help me avoid using my own database (for example a local sql)? I'm new to FIWARE Orion, and as far as I've read in the manuals, I can create entities and attributes associated with them, something amazing when using node-like entities such as sensors. But how can I store information about many authenticated users if it's mandatory to have a parent-child entity relation like this: user 1 -> car 1 -> cylinder 1 -> tempCyl.. Can I refer to "tempCyl" with only one request? Or is it mandatory to chain requests (for example set attribute child "tempCyl" to "cylinder 1" and vise-versa?

Also if under "user 1" entity, the information is sensitive, is there a way to protect data with a valid token (like OAuth for example)? Or do I have to create my own internal (non internet accessible) Orion instance?

Answer 1

The easier way of building relationships in an entity-attribute model like the one that Orion implements (e.g. relationship between A and B entitiesas) is to use some attribute in entity A to point to entity B, e.g. A.rel = B. If you need bi-directional relationship, then use also some attribute in B to point to A.

Regarding sensible information, Orion implements a multitenancy mechanism that allowa to partition different set of context information using the same Orion instance. Isolation is done in per-DB basic and can be combined with the FIWARE security framework so only the users beloning to a tenant can access information in that tenant but not the others (have a look to the Orion's PEP documentation).