Before we examine Consolidation, the next step in the journey to cloud, let's take a short detour to address a critical choice you will face at the outset of your journey: whether to deploy your databases in virtual machines or not.

A common misconception we've encountered is the belief that moving to cloud computing can be accomplished by simply hosting one's current operating environment as-is within virtual machines, and then stacking those VMs together in a consolidated environment.  This solution is often described as "Infrastructure as a Service" (IaaS) because the building block for deployments is a VM, which behaves like a full complement of infrastructure.  This approach is easy to understand and may feel like a good first step, but it won't take your databases very far in the journey to cloud computing.  In fact, if you follow the IaaS fork in the road, your journey will end quickly, without realizing the full benefits of cloud computing. 

The better option to is to rationalize the deployment stack so that VMs are needed only for exceptional cases.  By settling on a standard operating system and patch level, you create an infrastructure that potentially all of your databases can share.  Now, the building block will be database instances or possibly schemas within databases.  These components are the platforms on which you will deploy workloads, hence this is known as "Platform as a Service" (PaaS).

PaaS opens the door to higher degrees of consolidation than IaaS, because with PaaS you will not need to accommodate the footprint (operating system, hypervisor, processes, ...) that each VM brings with it.  You will also reduce your maintenance overheard if you move forward without the VMs and their O/Ses to patch and monitor.  So while IaaS simply shuffles complex and varied environments into VMs,  PaaS actually reduces complexity by rationalizing to the small possible set of components. 

Now we're ready to look at the consolidation options that PaaS provides -- in our next blog posting.