Don't think it can be hidden unless you go the route of hiding the application window, and even then, not sure. I wouldn't worry about it if you're the only user because all it means is that "I'm busy doing what you asked me to do, so stop poking around or asking for something else until I'm done." It's not a crash thing, or an error of any kind.
OK, one exception about something that may provide some relief is to make sure your query or other operation is as efficient as it can be, or parse it into tasks. I doubt there is an API for working with an array, but if there is, that might help.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.