How would you version addresses and why?

How would you version addresses and why?

• A. Version with AddressHistory or a version field to preserve past states; active pointer for current data; enable retrieval of historical states and backward compatibility
• B. Overwrite previous addresses without history
• C. No versioning
• D. Use separate database per version

Answer: (A)

Versioning addresses means keeping a record of every past state and having a clear pointer to the current one. This approach is best because it preserves history, enabling you to reconstruct what an address looked like at any point in time, support audits, rollback changes if needed, and maintain compatibility with systems that rely on older data formats or states. Implementing this typically involves storing each address as a versioned record (either in an AddressHistory table or as a versioned field on the address record) and using an active pointer or a current flag to identify the live address. A common pattern is to include version numbers or valid_from/valid_to timestamps and an is_current flag. When an update occurs, you create a new version rather than overwriting the existing one, and you update the active pointer to the new version. This way, the historical versions remain immutable and queryable, so you can fetch the address as of a specific date or trace how an address changed over time. Why other approaches don’t fit as well: overwriting without history loses every bit of past data, making it impossible to know what was stored before or why a change occurred. No versioning eliminates traceability entirely. Using a separate database per version introduces heavy maintenance, data duplication, and complex cross-version querying, making it impractical for most applications. In short, versioning with a history store and a current pointer gives you both a reliable record of changes and convenient access to the latest data, along with the flexibility to audit or roll back if needed.

Versioning addresses means keeping a record of every past state and having a clear pointer to the current one. This approach is best because it preserves history, enabling you to reconstruct what an address looked like at any point in time, support audits, rollback changes if needed, and maintain compatibility with systems that rely on older data formats or states.

Implementing this typically involves storing each address as a versioned record (either in an AddressHistory table or as a versioned field on the address record) and using an active pointer or a current flag to identify the live address. A common pattern is to include version numbers or valid_from/valid_to timestamps and an is_current flag. When an update occurs, you create a new version rather than overwriting the existing one, and you update the active pointer to the new version. This way, the historical versions remain immutable and queryable, so you can fetch the address as of a specific date or trace how an address changed over time.

Why other approaches don’t fit as well: overwriting without history loses every bit of past data, making it impossible to know what was stored before or why a change occurred. No versioning eliminates traceability entirely. Using a separate database per version introduces heavy maintenance, data duplication, and complex cross-version querying, making it impractical for most applications.

In short, versioning with a history store and a current pointer gives you both a reliable record of changes and convenient access to the latest data, along with the flexibility to audit or roll back if needed.