MySQL is the world's most popular open source database--simply the best for access.
Big Business has setup options to share data to with systems that can access MySQL. Your shipping station can get Orders to read shipping addresses and put back tracking.
If you have a web store you administer, you may want Items the instant they change. If your store is B2B, you may want Customers, too. It's up to you, what you can do.
Big Business 14.48 updates MySQL Access to add "non-blocking" options for Azure. Microsoft Azure is a cloud computing platform with option to run MySQL databases.