A photo marketplace stores originals and edited versions of each image. Prior file versions must stay recoverable for 90 days and then be removed without manual work. Which design meets this?
Show answer and explanation
Answer: A
Cloud Storage supports object versioning, which keeps prior generations of an object when it is overwritten or deleted. A lifecycle rule can target noncurrent versions by age, such as deleting them 90 days after they became noncurrent, which automates cleanup without a custom job. Cloud SQL and Firestore are built for relational rows and documents, where large binary payloads are costly and hit size limits, and Bigtable cells have size limits and are not a media store.
Why the other options are wrong
- B. BLOBs inflate database storage and backups, and a backup table is a manual copy process rather than automatic version retention with expiry.
- C. Base64 encoding inflates binary data by about a third and Firestore documents are capped at 1 MiB, so large images cannot be stored there.
- D. Bigtable's cell versioning is governed by garbage-collection rules on cells, which is not object versioning with lifecycle expiry, and cells are capped at 100 MiB.