i am willing to do certification in oracle (OCA).If you're willing to take the certification, then Oracle is willing to allow you to try.
so does it have validity period like CISCO certifications or it don't have ?There are no expiration dates for Oracle certifications. That said, many if not most are against specific versions of software that will, over time, become less valuable. For example, I am certified in Oracle release 7.3. However, this version is no longer widely used. Since I got that initial OCP certification, I have taken tests to upgrade it to releases 8i, 9i, 10G, and 11G.
and is OCA worth getting ?Ask ten different people and you'll get twelve different answers. That said, I'm a big supporter of IT certifications in general and Oracle ones in particular. I've written several articles on the subject. Two are below:
scope ?You haven't actually indicated which OCA you are referring to. I'm going to assume you mean the 11G Database administrator OCA. A link with information on that is: