Web Services is a powerful technology that enables different systems to communicate with each other over the Internet in a uniform way, without having to worry about implementation details. The most popular protocol for accessing web services today is SOAP—a lightweight, XML-based, messaging protocol designed for exchanging structured and typed information between distributed applications over standard transport protocols, such as HTTP.
When developing a SOAP web service to expose the functionality of a PHP/Oracle application, you have a number of choices. For example, you could employ the PEAR::SOAP package or the PHP SOAP extension to implement a SOAP web service in PHP while implementing its business logic partly in PHP and partly within the database. As far as Oracle is concerned, you might, of course, implement the key business logic of a SOAP web service within the database, while still having the SOAP server implemented in PHP and, therefore, running on the...