I would like to know, if a basic search of patent database will give me an idea on whether my idea is patent-able? or I need to perform any specific patentiblity search?
You can perform a patentability search by searching on Google patents and on the USPTO to figure out generally what has already been patented and what patent applications have been filed. However, in the US you when you file a patent application you can elect to not have anything published until the application issued as a patent as long as you agree to not file outside of the United States.
You can spend a small amount of time searching or a very large amount of time searching and may find some things but you may miss other things. Performing a search is generally a good idea, but it is not a failsafe. Keep in mind that you do not have to perform a search before filing an application, but it may save you time and money down the road because you may decide to not move forward with filing an application. In addition, if you do perform a search, and find related prior art, you have the duty of disclosing the related prior art to the USPTO.