Does Snowflake call the remote service directly when executing external functions?

• A. False
• B. True
• C. It calls a local stub
• D. It uses a built-in function

Answer: (A)

External functions let Snowflake run code outside the warehouse. When you call one, Snowflake doesn’t execute that external code itself. Instead, it sends a request to the configured remote endpoint through a secure integration, and the actual work is performed by the external service (for example, AWS Lambda, Azure Functions, etc.). Snowflake signs and forwards the input, waits for the remote service to respond, and then returns the result.

So this isn’t a direct, in-Snowflake execution of the remote logic, nor is it a built-in function or a local stub. The external service handles the business logic, while Snowflake acts as the requester and orchestrator.