Best practices for modelling Semantic DB Queries

Hi,

I have gone through the TWX data modelling and the concepts are pretty clear.
But, i could not find a clear solution when it comes to modelling external entities like Semantic DB in TWX data model.
I will try to phrase my question here;

1. I have 3 robots on the edge (with 3 different functionalities).

2. I have a Graph DB, where i store my data (like creating an order at Robot1, shutting down Robot2 etc.)

3. So, I have a set of Queries which handles basically the CRUD operations in my DB.

Now, the question is where to place these queries.

1. In a master Thing (central Thing), which handles all DB related activities.

OR

2. In a Thing Shape on individual Robot Thing Template layers (like getRobot2StatusFromDB() service).

Please provide your ideas on the best practices.

Thanks in advance