Do you keep talking?

When you’re at a restaurant and a waiter/waitress comes up to the table to provide a service that requires no interruption (like refilling water) do you continue whatever conversation you may be having and not acknowledge their general presence, or do you pause the conversation you’re having – either because it’s private, or simply to say “thank you” and acknowledge their presence? Does it depend on the kind of restaurant you’re in?

This question was actually inspired by multiple movies/TV shows that I’ve seen where, typically, the “fancy restaurant” patrons tend to acknowledge the servers a lot less frequently, so I guess I was curious to see how it carried over in reality with Jellies.