How should you model physical versus mailing addresses in data?

• A. Use a single flag to indicate physical vs mailing
• B. Use separate fields only
• C. Support both with a flag or separate fields and allow duplication if needed
• D. Treat them as the same address

Answer: (C)

When modeling addresses, you need to represent that one person can have more than one address role, such as a physical residence and a mailing address. The best approach is to store address data in a structured way and tag each address with its type, while allowing duplicates if the same location serves multiple roles.

This lets you capture both addresses when they differ (for example, a home address for living and a PO box for mail) and also handle cases where the same location serves both roles by reusing or duplicating the record as needed. It keeps the data flexible for future expansion to other address types (billing, shipping, etc.) and makes querying straightforward: you can fetch all addresses of a given type or understand the relationship between addresses and their purposes.

Choosing only a single flag misses the nuance of multiple address records; using only separate fields can complicate scenarios where a person has two distinct addresses or when the same address serves multiple roles; treating both roles as the same address ignores real-world differences in where mail is sent versus where someone lives.