For an application to be successfully distributed, it needs to adopt parts of a messaging architecture. Distributed applications need to allow access to information from a variety of locations, but users typically don't need quick response times. How updates and changes are distributed, or replicated, is critical to the success of an enterprise workflow system. Whether you choose a database architecture, a messaging architecture, or a blend depends on your particular needs. For example, for an airline reservation system, a database architecture is better, because a fixed set of people is accessing a fixed set of information.
Databases provide fast and robust access to structured data.
Don't overlook that databases are a mature, robust, and secure technology with lots of add-on tools and experienced programmers and managers. But a database architecture isn't always suitable. For example, for an information-publishing service, many different people will be downloading the information, which could be stored in files of any size and type, with graphics and video. Because databases are not flexible in handling unstructured data types and because many paths of communication exist, a messaging structure is better. When you have a distributed system, you need an efficient way to update each site.