need advice. datawarehousing or IBM mainframe ?

hi everybody,

can someone please advice me that which domain has a better scope from career point of view.
data warehousing or IBM mainframe ?

i have done B.tech in computers and now i want to pursue a course in either data warehousing or mainframe but i don't have any idea that which one has a better scope for getting the job.

please advice.
any help will be greatly appreciated.

also please tell me some good institutes in delhi/gurgaon/NCR/faridabad which provides good training in data warehousing or mainframe.