Operations in Node

Each request to a web server is taking 40 ms to complete and 35ms of that 40ms is database I/O that can be done asynchronously.

Which of the following operations will you use if you want that 35 ms per request to get freed up to handle other requests?

Options

1. Non-blocking asynchronous operations
2. Blocking asynchronous operations
3. Non-blocking synchronous operations
4. Blocking synchronous operations