ADA-C01 Question 240
Single answerIdentify use cases for cloning databases and tablesA financial services company needs to validate a schema migration against production data before a weekend release. The DBA must provide the QA team with a copy of the production SALES database immediately, without disrupting ongoing ETL workloads or incurring the time and storage cost of fully copying 40 TB of data. During testing, QA may create and drop tables, but production data must remain unchanged. Which approach best meets these requirements?
- A
Create a zero-copy clone of the SALES database for QA, and allow QA to perform testing in the cloned database.
- B
Replicate the SALES database to another region and have QA run tests against the replicated copy.
- C
Use Time Travel to query the SALES database from an earlier point in time while QA creates test objects in the production database.
- D
Unload the SALES database to external stage files and reload it into a new QA database.
Show answer and explanation
Correct answer: A
Explanation
The best answer is to create a zero-copy clone of the SALES database. Snowflake cloning is specifically designed for scenarios such as creating development, testing, QA, and sandbox environments from production data quickly and with minimal storage overhead. At clone creation time, Snowflake does not copy all table data; instead, the clone references the same underlying micro-partitions until changes are made, after which changed data diverges. This makes cloning ideal when teams need an isolated environment immediately but want to avoid long copy operations or large storage costs. In contrast, Time Travel is for accessing or restoring prior data states, not for provisioning a writable isolated environment, and replication is for continuity/distribution use cases rather than ad hoc QA validation. This aligns with Snowflake documentation and best practices for zero-copy cloning of databases, schemas, and tables.
- A. Correct.
Correct. A zero-copy clone creates a logically independent copy of a database, schema, or table almost instantly by reusing the existing micro-partitions rather than physically duplicating all underlying data at creation time. This is a primary use case for cloning: quickly provisioning isolated environments such as QA, development, or release validation based on current production data. Because the clone is independent at the object level, QA can create, modify, and drop objects in the clone without affecting production. Additional storage is only consumed for changed data after cloning.
- B. Incorrect.
Incorrect. Database replication is intended for account-level business continuity, disaster recovery, and cross-region or cross-cloud data distribution scenarios, not for rapid local test environment creation. Replication also introduces more administrative overhead and does not address the requirement for immediate, low-overhead provisioning as directly as zero-copy cloning. A candidate might choose this option because it does create another copy-like environment, but it is not the best tool for this use case.
- C. Incorrect.
Incorrect. Time Travel allows querying or restoring historical data states, but it does not provide an isolated writable test environment. QA creating test objects in the production database violates the requirement to keep production unchanged and avoid disruption. This option reflects the common misconception that Time Travel can replace cloning for environment provisioning; in reality, it is designed for data recovery and historical access, not for safe, independent testing workspaces.
- D. Incorrect.
Incorrect. Unloading and reloading data would create a separate environment, but it is slower, operationally heavier, and typically more expensive than cloning for a 40 TB database. It also introduces unnecessary data movement and processing, which conflicts with the requirement to provide the copy immediately and avoid the time and storage cost of a full copy. Someone might pick this if they are thinking in terms of traditional ETL duplication rather than Snowflake's zero-copy clone capability.