Go to Apple.com and see if your 2012 MBA works with Mavericks! Since you're not giving specs of your MBA it is difficult for anyone to give to the answer!
Here are the requirements from Apple. I installed Mavs on my daughter's 2008 Macbook and it works just fine and that machine has far less power than yours. You will be fine.
Of course it will work fine. I have it installed on my 2012 MBA (11", 4GB, 480 SSD) and on my 5,1 Mac Pro. The Mac Pro also has Yosemite installed on another internal start-up disk. This thread asks a similar question to the OPs.