When you are new to Oracle, you want to minimize the number of unknowns you throw into the mix. As such, you should probably start the learning process on the operating system you are most familiar with. If you are happiest on Windows, then by all means try the Windows downloads of Oracle Database . It's a good way to get into the product, without having to start learning any new OS technology. The vast majority of Oracle systems I have worked with have been installed on some form of UNIX or Linux, so you will definitely need to familiarize yourself with those at some point, but for now, stick with what you know.

I think the Oracle Certified Professional (OCP) certification is a pretty good starting point for any aspiring DBA. It's not perfect and achieving the certification doesn't make you a great DBA, but if you approach it in the right way it will have taken the first steps along the right path. You can read more about the OCP in the following articles. - Oracle Certification : Frequently Asked Questions (OCA, OCP, OCE, OCM) - Oracle Database OCA & OCP Certification

As a DBA you will be working on a variety of operating systems. A good way to get a feel for new operating systems is to try playing about with Oracle VirtualBox . It will allow you to run multiple virtual machines with different operating systems on your PC, giving you an opportunity to get more familiar with them in a safe environment. This will also be a stepping stone to doing more complicated stuff later. There is a basic example of creating a VM using VirtualBox here . I've written a number of basic installation guides for Linux, which you can find here . I would suggest you play about with building a few VMs, installing Windows and a variety of Linux distros, including Oracle Linux versions, Ubuntu, maybe Fedora too. It's not important to go into too much depth with any of these Linux distributions at first. This is more about cutting your teeth on VirtualBox. Doing a variety of things will help you understand virtualization generally and the product itself. You might also benefit from reading a basic introduction to virtualization, like my article here .

Following on from the previous step, once you are feeling comfortable with the basics of being an Oracle DBA and virtualization, you should probably start to broaden your knowledge of operating systems. This is especially true if your primary learning platform was Windows. Most of the work you do as an Oracle DBA will be on UNIX and Linux systems, so you really need to be comfortable on those. The easiest way into that is to use Oracle Linux , which is free and supported. I've already linked to creation of a VM and installation articles for various Linux distributions, including Oracle Linux, but you really need to know a bit more about Linux itself if you are serious about being a DBA on it. You can read a whole bunch of stuff about it here . The better your grounding in Linux, the easier you will find more complex tasks, like RAC installations, in the future.

Once you feel happy with VirtualBox and installation of Linux on VMs, you can consider doing a simple Oracle installation on a Linux VM. Something like those described here . Personally, I would stick with Oracle on the basic file system at first, avoiding more complex features like ASM until you are more confident. Play about with this stuff. Break it and try to fix it. Do backup and recovery. Do multiple installations. Try upgrades of the database and OS etc. Try to mimic normal DBA tasks. Don't just assume one successful installation means you're ready to move on.

When you are feeling confident with that basic stuff, you can consider looking at installations using Automatic Storage Manager (ASM) . The use of ASM means you will need some aspects of the Grid Infrastructure technology, which is your stepping stone to Real Application Cluster (RAC) installations. If you invest some time in understanding ASM and Grid Infrastructure technologies like Oracle restart, the progression to RAC will be much easier.

When all the previous ground work has been done and you want a bigger challenge you can consider a virtual RAC installation. There are some examples of these on this website here . Oracle RAC requires some knowledge in a number of areas, including operating systems and networking. Without those you will make a lot of mistakes and find the process incredibly infuriating. If you have taken your time to learn all the prerequisites, it will feel like a natural progression. - How To Learn Real Application Clusters (RAC) Administration

So now you have the choice: - Work your way methodically through the technology stack. Read the manuals as you go and test stuff. Build a good foundation that will help you progress, have ideas of your own and become a good DBA. - Race through trying to install RAC as quickly as possible. Write lots of posts to forums complaining how stuff doesn't work, how difficult Oracle is and how rubbish people's articles are because they didn't hand-hold you through doing something that you probably shouldn't have been attempting in the first place. At the end of this you will have very little real knowledge and will probably not be capable of doing anything meaningful as a DBA in a work environment. The choice is yours. Choose wisely. :) For more information see: - Oracle Certification : Frequently Asked Questions (OCA, OCP, OCE, OCM) - Oracle Database OCA & OCP Certification - VirtualBox : Creating a New Virtual Machine (VM) - Operating System Installations - A Cure for Virtual Insanity - Oracle Linux : Frequently Asked Questions (FAQs) - RHCSA and RHCE - Linux Articles - Automatic Storage Management (ASM) - Real Application Clusters (RAC) Hope this helps. Regards Tim...