Thank you Janos. In other words, this is something that can be done only or with help of BASIS team. ABAP developer, even though there is an option to change Data Class from SE11 and SE14 adjustment, cannot make any difference.
That make sense for various reasons. But, some how I see a little gap (may be in my understanding!) why changing "data class" from SE11 is not replicating at data base level.
Regards,
Naveen