No. You can have unlimited products and no limitations on the database structure based in your requirement and budget. However, the major limiting factor here would-be server resources. You may have to go for some external systems to rapidly update broad swathes of the product catalog. For instance, if your product attributes are complex, you may need a remote file store for the product images. This would also help in the easy loading of the products. Skynet Technologies have a Drupal Commerce developers’ team to help you scale.