Using a legitimate study aid provided by a training organization (like Aviation Exam or BGS) is exactly the same as a law student using "BarBri" or a med student using "UWorld." It is commercial study preparation .
For any aspiring airline pilot, the journey to obtaining the Airline Transport Pilot License (ATPL) is arguably the most intellectually demanding phase of training. It is a rite of passage that separates the casual flyer from the professional commander of a multi-crew jet.
Do not buy a database to cheat the system. Buy a database to challenge the system. When you sit for your Meteorology exam and a complex question about a cold front occlusion appears—a question you have seen in four different variations—you will smile. Not because you memorized the letter "C," but because you truly understand the physics of the atmosphere.