Unit 3: Relational and Non-Relational Data

Data storage is an architecture decision. The useful question is not “Which database is better?” It is “What relationships, queries, and changes does this system need to survive?”

Source lessons

1. Working with Data: Relational Databases
2. Working with Data: Non-Relational Data

Study both models before choosing one. Pay attention to structure, relationships, query patterns, and the cost of changing the data model later.

What you should be able to prove

By the end of the Unit, you should be able to:

• identify entities, fields, and relationships in a data problem;
• sketch both a relational and a document-oriented representation;
• name the queries that matter to the system; and
• defend a storage choice using requirements instead of slogans.

Evidence check

Finish with Evidence Check — Choose the Data Model. You will model the same robotics-team information two ways and write a short architecture decision.

Runtime boundary

No database server is required. The evidence check is intentionally a design exercise so the core course remains accessible without infrastructure.