As with many widely hyped areas, there is much more variation within the broad spectrum of products referred to as “Cloud” that is immediately apparent. This variation is evident in one of the key misunderstandings about the Oracle Database Cloud Service.

People could be forgiven for thinking that the Database Cloud Service was a Database-as-a-Service (DBaaS), but this is actually not true. The Database Cloud Service is a Platform-as-a-Service, which presents a different user and developer interface and has a different set of qualities.

A good way to think about the difference between these two varieties of Cloud offerings is that you, the customer, have to deal with things at the level of the offering, but not for anything below it. In practice, this means that you do not have to deal with hardware or system software, including installation and maintenance, for DBaaS. You also do not have much control over configuration of these options.

For PaaS, you don’t have to deal with hardware, system software, or database software – and also do not have control over these levels in the stack. So you cannot modify configuration parameters for the database with the Database Cloud Service – your interface is through SQL and PL/SQL, with Application Express, included in the Database Cloud Service, or through JDBC for Java apps running in the Java Cloud Service, or through RESTful Web Services.

You will notice what is not mentioned there – SQL*Net. You cannot access your Oracle Database Cloud Service by changing an entry in the TNSNames file and using SQL*Net. So the effort involved in migrating an existing Oracle Database in your data center to the Database Cloud Service may be prohibitive.

The good news is that Application Express and the RESTful Web Services wizard in the Database Cloud Service allow you to develop new applications very quickly, and, of course, the provisioning of the entire Database Cloud Service takes only minutes.